diff --git a/src/agents/builtin-agents/hephaestus-agent.ts b/src/agents/builtin-agents/hephaestus-agent.ts
index a32064c63..c05b1fa71 100644
--- a/src/agents/builtin-agents/hephaestus-agent.ts
+++ b/src/agents/builtin-agents/hephaestus-agent.ts
@@ -8,6 +8,7 @@ import { applyEnvironmentContext } from "./environment-context"
 import { applyCategoryOverride, mergeAgentConfig } from "./agent-overrides"
 import { applyModelResolution, getFirstFallbackModel } from "./model-resolution"
 import { getGptApplyPatchPermission } from "../gpt-apply-patch-guard"
+import { applyFrontierToolSchemaPermission } from "../frontier-tool-schema-guard"
 
 export function maybeCreateHephaestusConfig(input: {
   disabledAgents: string[]
@@ -89,6 +90,13 @@ export function maybeCreateHephaestusConfig(input: {
   }
 
   const resolvedModel = hephaestusConfig.model ?? ""
+  hephaestusConfig.permission = applyFrontierToolSchemaPermission(
+    hephaestusConfig.permission,
+    resolvedModel,
+    hephaestusOverride?.permission,
+    (hephaestusOverride as { tools?: Record<string, boolean> } | undefined)?.tools
+  )
+
   const gptDeny = getGptApplyPatchPermission(resolvedModel)
   if (Object.keys(gptDeny).length > 0 && hephaestusConfig.permission) {
     Object.assign(hephaestusConfig.permission, gptDeny)
diff --git a/src/agents/builtin-agents/sisyphus-agent.test.ts b/src/agents/builtin-agents/sisyphus-agent.test.ts
index e7289f6c0..b32ede5af 100644
--- a/src/agents/builtin-agents/sisyphus-agent.test.ts
+++ b/src/agents/builtin-agents/sisyphus-agent.test.ts
@@ -1,3 +1,5 @@
+/// <reference types="bun-types" />
+
 import { describe, expect, test } from "bun:test";
 import { maybeCreateSisyphusConfig } from "./sisyphus-agent";
 import type { AgentOverrides } from "../types";
@@ -12,7 +14,7 @@ describe("maybeCreateSisyphusConfig", () => {
           model: "openai/gpt-5.4",
           permission: {
             apply_patch: "allow",
-          },
+          } as Record<string, "allow">,
         },
       };
       const mergedCategories: Record<string, CategoryConfig> = {};
@@ -46,7 +48,7 @@ describe("maybeCreateSisyphusConfig", () => {
           model: "anthropic/claude-opus-4-7",
           permission: {
             apply_patch: "allow",
-          },
+          } as Record<string, "allow">,
         },
       };
       const mergedCategories: Record<string, CategoryConfig> = {};
@@ -73,6 +75,178 @@ describe("maybeCreateSisyphusConfig", () => {
     });
   });
 
+  describe("#given Opus 4.7 model with user override allowing grep and glob", () => {
+    test("#when config is created #then grep and glob are still denied", () => {
+      // given
+      const agentOverrides: AgentOverrides = {
+        sisyphus: {
+          model: "anthropic/claude-opus-4-7",
+          permission: {
+            grep: "allow",
+            glob: "allow",
+          } as Record<string, "allow">,
+        },
+      };
+      const mergedCategories: Record<string, CategoryConfig> = {};
+
+      // when
+      const config = maybeCreateSisyphusConfig({
+        disabledAgents: [],
+        agentOverrides,
+        availableModels: new Set(["anthropic/claude-opus-4-7"]),
+        systemDefaultModel: "anthropic/claude-opus-4-7",
+        isFirstRunNoCache: false,
+        availableAgents: [],
+        availableSkills: [],
+        availableCategories: [],
+        mergedCategories,
+        useTaskSystem: false,
+      });
+
+      // then
+      expect(config?.permission).toHaveProperty("grep", "deny");
+      expect(config?.permission).toHaveProperty("glob", "deny");
+    });
+  });
+
+  describe("#given GPT 5.5 model with user override allowing grep and glob", () => {
+    test("#when config is created #then grep and glob are still denied", () => {
+      // given
+      const agentOverrides: AgentOverrides = {
+        sisyphus: {
+          model: "openai/gpt-5.5",
+          permission: {
+            grep: "allow",
+            glob: "allow",
+          } as Record<string, "allow">,
+        },
+      };
+      const mergedCategories: Record<string, CategoryConfig> = {};
+
+      // when
+      const config = maybeCreateSisyphusConfig({
+        disabledAgents: [],
+        agentOverrides,
+        availableModels: new Set(["openai/gpt-5.5"]),
+        systemDefaultModel: "openai/gpt-5.5",
+        isFirstRunNoCache: false,
+        availableAgents: [],
+        availableSkills: [],
+        availableCategories: [],
+        mergedCategories,
+        useTaskSystem: false,
+      });
+
+      // then
+      expect(config?.permission).toHaveProperty("grep", "deny");
+      expect(config?.permission).toHaveProperty("glob", "deny");
+    });
+  });
+
+  describe("#given frontier default model with category override to non-frontier model", () => {
+    test("#when config is created #then stale grep and glob denies are cleared", () => {
+      // given
+      const agentOverrides: AgentOverrides = {
+        sisyphus: {
+          category: "non-frontier",
+        },
+      };
+      const mergedCategories: Record<string, CategoryConfig> = {
+        "non-frontier": {
+          model: "openai/gpt-5.4",
+        },
+      };
+
+      // when
+      const config = maybeCreateSisyphusConfig({
+        disabledAgents: [],
+        agentOverrides,
+        availableModels: new Set(["anthropic/claude-opus-4-7", "openai/gpt-5.4"]),
+        systemDefaultModel: "anthropic/claude-opus-4-7",
+        isFirstRunNoCache: false,
+        availableAgents: [],
+        availableSkills: [],
+        availableCategories: [],
+        mergedCategories,
+        useTaskSystem: false,
+      });
+
+      // then
+      expect(config?.model).toBe("openai/gpt-5.4");
+      expect(config?.permission).not.toHaveProperty("grep");
+      expect(config?.permission).not.toHaveProperty("glob");
+    });
+  });
+
+  describe("#given non-frontier model with user override denying grep and glob", () => {
+    test("#when config is created #then explicit user denies are preserved", () => {
+      // given
+      const agentOverrides: AgentOverrides = {
+        sisyphus: {
+          model: "openai/gpt-5.4",
+          permission: {
+            grep: "deny",
+            glob: "deny",
+          } as Record<string, "deny">,
+        },
+      };
+      const mergedCategories: Record<string, CategoryConfig> = {};
+
+      // when
+      const config = maybeCreateSisyphusConfig({
+        disabledAgents: [],
+        agentOverrides,
+        availableModels: new Set(["openai/gpt-5.4"]),
+        systemDefaultModel: "openai/gpt-5.4",
+        isFirstRunNoCache: false,
+        availableAgents: [],
+        availableSkills: [],
+        availableCategories: [],
+        mergedCategories,
+        useTaskSystem: false,
+      });
+
+      // then
+      expect(config?.permission).toHaveProperty("grep", "deny");
+      expect(config?.permission).toHaveProperty("glob", "deny");
+    });
+  });
+
+  describe("#given non-frontier model with legacy user tools denying grep and glob", () => {
+    test("#when config is created #then explicit legacy denies are preserved", () => {
+      // given
+      const legacyOverride = {
+        model: "openai/gpt-5.4",
+        tools: {
+          grep: false,
+          glob: false,
+        },
+      };
+      const agentOverrides: AgentOverrides = {
+        sisyphus: legacyOverride,
+      };
+      const mergedCategories: Record<string, CategoryConfig> = {};
+
+      // when
+      const config = maybeCreateSisyphusConfig({
+        disabledAgents: [],
+        agentOverrides,
+        availableModels: new Set(["openai/gpt-5.4"]),
+        systemDefaultModel: "openai/gpt-5.4",
+        isFirstRunNoCache: false,
+        availableAgents: [],
+        availableSkills: [],
+        availableCategories: [],
+        mergedCategories,
+        useTaskSystem: false,
+      });
+
+      // then
+      expect(config?.permission).toHaveProperty("grep", "deny");
+      expect(config?.permission).toHaveProperty("glob", "deny");
+    });
+  });
+
   describe("#given generic GPT model with user override allowing apply_patch", () => {
     test("#when config is created #then apply_patch is still denied", () => {
       // given
@@ -81,7 +255,7 @@ describe("maybeCreateSisyphusConfig", () => {
           model: "openai/gpt-4o",
           permission: {
             apply_patch: "allow",
-          },
+          } as Record<string, "allow">,
         },
       };
       const mergedCategories: Record<string, CategoryConfig> = {};
diff --git a/src/agents/builtin-agents/sisyphus-agent.ts b/src/agents/builtin-agents/sisyphus-agent.ts
index 97aef5f61..6cb91370f 100644
--- a/src/agents/builtin-agents/sisyphus-agent.ts
+++ b/src/agents/builtin-agents/sisyphus-agent.ts
@@ -8,6 +8,7 @@ import { applyOverrides } from "./agent-overrides"
 import { applyModelResolution, getFirstFallbackModel } from "./model-resolution"
 import { createSisyphusAgent } from "../sisyphus"
 import { getGptApplyPatchPermission } from "../gpt-apply-patch-guard"
+import { applyFrontierToolSchemaPermission } from "../frontier-tool-schema-guard"
 
 export function maybeCreateSisyphusConfig(input: {
   disabledAgents: string[]
@@ -83,6 +84,13 @@ export function maybeCreateSisyphusConfig(input: {
   sisyphusConfig = applyOverrides(sisyphusConfig, sisyphusOverride, mergedCategories, directory)
 
   const resolvedModel = sisyphusConfig.model ?? ""
+  sisyphusConfig.permission = applyFrontierToolSchemaPermission(
+    sisyphusConfig.permission,
+    resolvedModel,
+    sisyphusOverride?.permission,
+    (sisyphusOverride as { tools?: Record<string, boolean> } | undefined)?.tools
+  )
+
   const gptDeny = getGptApplyPatchPermission(resolvedModel)
   if (Object.keys(gptDeny).length > 0 && sisyphusConfig.permission) {
     Object.assign(sisyphusConfig.permission, gptDeny)
diff --git a/src/agents/frontier-tool-schema-guard.ts b/src/agents/frontier-tool-schema-guard.ts
new file mode 100644
index 000000000..68158149a
--- /dev/null
+++ b/src/agents/frontier-tool-schema-guard.ts
@@ -0,0 +1,41 @@
+import type { AgentConfig } from "@opencode-ai/sdk"
+import { isGpt5_5Model } from "./types"
+import type { PermissionValue } from "../shared/permission-compat"
+
+const FRONTIER_TOOL_SCHEMA_NAMES = ["grep", "glob"] as const
+type MutablePermission = Record<string, PermissionValue | Record<string, PermissionValue>>
+
+function isOpus47Model(model: string): boolean {
+  const modelName = model.includes("/") ? (model.split("/").pop() ?? model) : model
+  return modelName.toLowerCase().includes("claude-opus-4-7")
+}
+
+export function getFrontierToolSchemaPermission(model: string): Record<string, "deny"> {
+  return isOpus47Model(model) || isGpt5_5Model(model)
+    ? { grep: "deny" as const, glob: "deny" as const }
+    : {}
+}
+
+export function applyFrontierToolSchemaPermission(
+  permission: AgentConfig["permission"] | undefined,
+  model: string,
+  explicitPermission?: AgentConfig["permission"],
+  explicitTools?: Record<string, boolean>
+): AgentConfig["permission"] | undefined {
+  if (!permission) return permission
+
+  const nextPermission: MutablePermission = { ...permission }
+  const explicitPermissionMap = explicitPermission as MutablePermission | undefined
+  const frontierDeny = getFrontierToolSchemaPermission(model)
+  if (Object.keys(frontierDeny).length > 0) {
+    Object.assign(nextPermission, frontierDeny)
+    return nextPermission as AgentConfig["permission"]
+  }
+
+  for (const toolName of FRONTIER_TOOL_SCHEMA_NAMES) {
+    if (explicitPermissionMap?.[toolName] === "deny") continue
+    if (explicitTools?.[toolName] === false) continue
+    delete nextPermission[toolName]
+  }
+  return nextPermission as AgentConfig["permission"]
+}
diff --git a/src/agents/hephaestus/agent.test.ts b/src/agents/hephaestus/agent.test.ts
index f7d1087f6..ca1d65c01 100644
--- a/src/agents/hephaestus/agent.test.ts
+++ b/src/agents/hephaestus/agent.test.ts
@@ -1,3 +1,5 @@
+/// <reference types="bun-types" />
+
 import { describe, expect, test } from "bun:test";
 import {
   getHephaestusPromptSource,
@@ -321,7 +323,7 @@ describe("maybeCreateHephaestusConfig GPT apply_patch guard", () => {
           model: "openai/gpt-5.4",
           permission: {
             apply_patch: "allow",
-          },
+          } as Record<string, "allow">,
         },
       };
       const mergedCategories: Record<string, CategoryConfig> = {};
@@ -355,7 +357,7 @@ describe("maybeCreateHephaestusConfig GPT apply_patch guard", () => {
           model: "anthropic/claude-opus-4-7",
           permission: {
             apply_patch: "allow",
-          },
+          } as Record<string, "allow">,
         },
       };
       const mergedCategories: Record<string, CategoryConfig> = {};
@@ -389,7 +391,7 @@ describe("maybeCreateHephaestusConfig GPT apply_patch guard", () => {
           model: "openai/gpt-4o",
           permission: {
             apply_patch: "allow",
-          },
+          } as Record<string, "allow">,
         },
       };
       const mergedCategories: Record<string, CategoryConfig> = {};
@@ -414,4 +416,176 @@ describe("maybeCreateHephaestusConfig GPT apply_patch guard", () => {
       expect(config?.permission).toHaveProperty("apply_patch", "deny");
     });
   });
+
+  describe("#given Opus 4.7 model with user override allowing grep and glob", () => {
+    test("#when config is created #then grep and glob are still denied", () => {
+      // given
+      const agentOverrides: AgentOverrides = {
+        hephaestus: {
+          model: "anthropic/claude-opus-4-7",
+          permission: {
+            grep: "allow",
+            glob: "allow",
+          } as Record<string, "allow">,
+        },
+      };
+      const mergedCategories: Record<string, CategoryConfig> = {};
+
+      // when
+      const config = maybeCreateHephaestusConfig({
+        disabledAgents: [],
+        agentOverrides,
+        availableModels: new Set(["anthropic/claude-opus-4-7"]),
+        systemDefaultModel: "anthropic/claude-opus-4-7",
+        isFirstRunNoCache: false,
+        availableAgents: [],
+        availableSkills: [],
+        availableCategories: [],
+        mergedCategories,
+        useTaskSystem: false,
+      });
+
+      // then
+      expect(config?.permission).toHaveProperty("grep", "deny");
+      expect(config?.permission).toHaveProperty("glob", "deny");
+    });
+  });
+
+  describe("#given GPT 5.5 model with user override allowing grep and glob", () => {
+    test("#when config is created #then grep and glob are still denied", () => {
+      // given
+      const agentOverrides: AgentOverrides = {
+        hephaestus: {
+          model: "openai/gpt-5.5",
+          permission: {
+            grep: "allow",
+            glob: "allow",
+          } as Record<string, "allow">,
+        },
+      };
+      const mergedCategories: Record<string, CategoryConfig> = {};
+
+      // when
+      const config = maybeCreateHephaestusConfig({
+        disabledAgents: [],
+        agentOverrides,
+        availableModels: new Set(["openai/gpt-5.5"]),
+        systemDefaultModel: "openai/gpt-5.5",
+        isFirstRunNoCache: false,
+        availableAgents: [],
+        availableSkills: [],
+        availableCategories: [],
+        mergedCategories,
+        useTaskSystem: false,
+      });
+
+      // then
+      expect(config?.permission).toHaveProperty("grep", "deny");
+      expect(config?.permission).toHaveProperty("glob", "deny");
+    });
+  });
+
+  describe("#given frontier default model with category override to non-frontier model", () => {
+    test("#when config is created #then stale grep and glob denies are cleared", () => {
+      // given
+      const agentOverrides: AgentOverrides = {
+        hephaestus: {
+          category: "non-frontier",
+        },
+      };
+      const mergedCategories: Record<string, CategoryConfig> = {
+        "non-frontier": {
+          model: "openai/gpt-5.4",
+        },
+      };
+
+      // when
+      const config = maybeCreateHephaestusConfig({
+        disabledAgents: [],
+        agentOverrides,
+        availableModels: new Set(["openai/gpt-5.5", "openai/gpt-5.4"]),
+        systemDefaultModel: "openai/gpt-5.5",
+        isFirstRunNoCache: false,
+        availableAgents: [],
+        availableSkills: [],
+        availableCategories: [],
+        mergedCategories,
+        useTaskSystem: false,
+      });
+
+      // then
+      expect(config?.model).toBe("openai/gpt-5.4");
+      expect(config?.permission).not.toHaveProperty("grep");
+      expect(config?.permission).not.toHaveProperty("glob");
+    });
+  });
+
+  describe("#given non-frontier model with user override denying grep and glob", () => {
+    test("#when config is created #then explicit user denies are preserved", () => {
+      // given
+      const agentOverrides: AgentOverrides = {
+        hephaestus: {
+          model: "openai/gpt-5.4",
+          permission: {
+            grep: "deny",
+            glob: "deny",
+          } as Record<string, "deny">,
+        },
+      };
+      const mergedCategories: Record<string, CategoryConfig> = {};
+
+      // when
+      const config = maybeCreateHephaestusConfig({
+        disabledAgents: [],
+        agentOverrides,
+        availableModels: new Set(["openai/gpt-5.4"]),
+        systemDefaultModel: "openai/gpt-5.4",
+        isFirstRunNoCache: false,
+        availableAgents: [],
+        availableSkills: [],
+        availableCategories: [],
+        mergedCategories,
+        useTaskSystem: false,
+      });
+
+      // then
+      expect(config?.permission).toHaveProperty("grep", "deny");
+      expect(config?.permission).toHaveProperty("glob", "deny");
+    });
+  });
+
+  describe("#given non-frontier model with legacy user tools denying grep and glob", () => {
+    test("#when config is created #then explicit legacy denies are preserved", () => {
+      // given
+      const legacyOverride = {
+        model: "openai/gpt-5.4",
+        tools: {
+          grep: false,
+          glob: false,
+        },
+      };
+      const agentOverrides: AgentOverrides = {
+        hephaestus: legacyOverride,
+      };
+      const mergedCategories: Record<string, CategoryConfig> = {};
+
+      // when
+      const config = maybeCreateHephaestusConfig({
+        disabledAgents: [],
+        agentOverrides,
+        availableModels: new Set(["openai/gpt-5.4"]),
+        systemDefaultModel: "openai/gpt-5.4",
+        isFirstRunNoCache: false,
+        availableAgents: [],
+        availableSkills: [],
+        availableCategories: [],
+        mergedCategories,
+        useTaskSystem: false,
+      });
+
+      // then
+      expect(config?.permission).toHaveProperty("grep", "deny");
+      expect(config?.permission).toHaveProperty("glob", "deny");
+    });
+  });
 });
diff --git a/src/agents/hephaestus/agent.ts b/src/agents/hephaestus/agent.ts
index b348f30b7..3aa773bac 100644
--- a/src/agents/hephaestus/agent.ts
+++ b/src/agents/hephaestus/agent.ts
@@ -9,6 +9,7 @@ import type {
 } from "../dynamic-agent-prompt-builder";
 import { categorizeTools, buildAgentIdentitySection } from "../dynamic-agent-prompt-builder";
 import { getGptApplyPatchPermission } from "../gpt-apply-patch-guard";
+import { getFrontierToolSchemaPermission } from "../frontier-tool-schema-guard";
 
 import { buildHephaestusPrompt as buildGptPrompt } from "./gpt";
 import { buildHephaestusPrompt as buildGpt53CodexPrompt } from "./gpt-5-3-codex";
@@ -139,6 +140,7 @@ export function createHephaestusAgent(
     permission: {
       question: "allow",
       call_omo_agent: "deny",
+      ...getFrontierToolSchemaPermission(model),
       ...getGptApplyPatchPermission(model),
     } as AgentConfig["permission"],
     reasoningEffort: "medium",
diff --git a/src/agents/sisyphus.ts b/src/agents/sisyphus.ts
index 21a36b8a0..d0bfb0979 100644
--- a/src/agents/sisyphus.ts
+++ b/src/agents/sisyphus.ts
@@ -13,6 +13,7 @@ import { buildGpt54SisyphusPrompt } from "./sisyphus/gpt-5-4";
 import { buildGpt55SisyphusPrompt } from "./sisyphus/gpt-5-5";
 import { buildTaskManagementSection } from "./sisyphus/default";
 import { getGptApplyPatchPermission } from "./gpt-apply-patch-guard";
+import { getFrontierToolSchemaPermission } from "./frontier-tool-schema-guard";
 
 const MODE: AgentMode = "primary";
 export const SISYPHUS_PROMPT_METADATA: AgentPromptMetadata = {
@@ -501,6 +502,7 @@ export function createSisyphusAgent(
       permission: {
         question: "allow",
         call_omo_agent: "deny",
+        ...getFrontierToolSchemaPermission(model),
         ...getGptApplyPatchPermission(model),
       } as AgentConfig["permission"],
       reasoningEffort: "medium",
@@ -527,6 +529,7 @@ export function createSisyphusAgent(
       permission: {
         question: "allow",
         call_omo_agent: "deny",
+        ...getFrontierToolSchemaPermission(model),
         ...getGptApplyPatchPermission(model),
       } as AgentConfig["permission"],
       reasoningEffort: "medium",
@@ -567,6 +570,7 @@ export function createSisyphusAgent(
   const permission = {
     question: "allow",
     call_omo_agent: "deny",
+    ...getFrontierToolSchemaPermission(model),
     ...getGptApplyPatchPermission(model),
   } as AgentConfig["permission"];
   const base = {
diff --git a/src/agents/tool-restrictions.test.ts b/src/agents/tool-restrictions.test.ts
index 3ae7bfcfe..1d0fed4fd 100644
--- a/src/agents/tool-restrictions.test.ts
+++ b/src/agents/tool-restrictions.test.ts
@@ -1,3 +1,5 @@
+/// <reference types="bun-types" />
+
 import { describe, test, expect } from "bun:test"
 import { createOracleAgent } from "./oracle"
 import { createLibrarianAgent } from "./librarian"
@@ -6,6 +8,7 @@ import { createMomusAgent } from "./momus"
 import { createMetisAgent } from "./metis"
 import { createAtlasAgent } from "./atlas"
 import { createSisyphusAgent } from "./sisyphus"
+import { createHephaestusAgent } from "./hephaestus"
 
 const TEST_MODEL = "anthropic/claude-sonnet-4-5"
 
@@ -131,4 +134,47 @@ describe("read-only agent tool restrictions", () => {
       expect(claudePermission["apply_patch"]).toBeUndefined()
     })
   })
+
+  describe("Sisyphus and Hephaestus frontier tool schema restrictions", () => {
+    test("deny grep and glob for Opus 4.7 and GPT 5.5 models", () => {
+      // given
+      const frontierAgents = [
+        createSisyphusAgent("anthropic/claude-opus-4-7"),
+        createSisyphusAgent("openai/gpt-5.5"),
+        createHephaestusAgent("anthropic/claude-opus-4-7"),
+        createHephaestusAgent("openai/gpt-5.5"),
+      ]
+
+      // when
+      const permissions = frontierAgents.map(
+        (agent) => (agent.permission ?? {}) as Record<string, string>,
+      )
+
+      // then
+      for (const permission of permissions) {
+        expect(permission.grep).toBe("deny")
+        expect(permission.glob).toBe("deny")
+      }
+    })
+
+    test("keeps grep and glob available for other models", () => {
+      // given
+      const otherAgents = [
+        createSisyphusAgent("anthropic/claude-sonnet-4-5"),
+        createSisyphusAgent("openai/gpt-5.4"),
+        createHephaestusAgent("openai/gpt-5.4"),
+      ]
+
+      // when
+      const permissions = otherAgents.map(
+        (agent) => (agent.permission ?? {}) as Record<string, string>,
+      )
+
+      // then
+      for (const permission of permissions) {
+        expect(permission.grep).toBeUndefined()
+        expect(permission.glob).toBeUndefined()
+      }
+    })
+  })
 })
diff --git a/src/features/tmux-subagent/manager.test.ts b/src/features/tmux-subagent/manager.test.ts
index e63f4bf4d..943f246fb 100644
--- a/src/features/tmux-subagent/manager.test.ts
+++ b/src/features/tmux-subagent/manager.test.ts
@@ -3,7 +3,7 @@ import { describe, test, expect, mock, beforeEach, spyOn, afterAll } from 'bun:t
 import type { TmuxConfig } from '../../config/schema'
 import type { WindowState, PaneAction } from './types'
 import type { ActionResult, ExecuteContext } from './action-executor'
-import type { TmuxUtilDeps } from './manager'
+import type { TmuxSessionManager as TmuxSessionManagerType, TmuxUtilDeps } from './manager'
 import * as sharedModule from '../../shared'
 
 type ExecuteActionsResult = {
@@ -287,20 +287,95 @@ describe('TmuxSessionManager', () => {
 
     test('falls back to default port when serverUrl has port 0', async () => {
       // given
-      mockIsInsideTmux.mockReturnValue(true)
-      const { TmuxSessionManager } = await import('./manager')
-      const ctx = {
-        ...createMockContext(),
-        serverUrl: new URL('http://127.0.0.1:0/'),
-      }
-      const config = createTmuxConfig({ enabled: true,
-      layout: 'main-vertical',
-      main_pane_size: 60,
-      main_pane_min_width: 80,
-      agent_pane_min_width: 40, })
+      const previousOpenCodePort = process.env.OPENCODE_PORT
+      delete process.env.OPENCODE_PORT
+      let manager: TmuxSessionManagerType | undefined
+      try {
+        mockIsInsideTmux.mockReturnValue(true)
+        const { TmuxSessionManager } = await import('./manager')
+        const ctx = {
+          ...createMockContext(),
+          serverUrl: new URL('http://127.0.0.1:0/'),
+        }
+        const config = createTmuxConfig({ enabled: true,
+        layout: 'main-vertical',
+        main_pane_size: 60,
+        main_pane_min_width: 80,
+        agent_pane_min_width: 40, })
 
-      // when
-      const manager = new TmuxSessionManager(ctx, config, mockTmuxDeps)
+        // when
+        manager = new TmuxSessionManager(ctx, config, mockTmuxDeps)
+      } finally {
+        if (previousOpenCodePort === undefined) {
+          delete process.env.OPENCODE_PORT
+        } else {
+          process.env.OPENCODE_PORT = previousOpenCodePort
+        }
+      }
+
+      // then
+      expect((manager as any).serverUrl).toBe('http://localhost:4096')
+    })
+
+    test('falls back to configured OPENCODE_PORT when serverUrl has port 0', async () => {
+      // given
+      const previousOpenCodePort = process.env.OPENCODE_PORT
+      process.env.OPENCODE_PORT = '5678'
+      let manager: TmuxSessionManagerType | undefined
+      try {
+        mockIsInsideTmux.mockReturnValue(true)
+        const { TmuxSessionManager } = await import('./manager')
+        const ctx = {
+          ...createMockContext(),
+          serverUrl: new URL('http://127.0.0.1:0/'),
+        }
+        const config = createTmuxConfig({ enabled: true,
+        layout: 'main-vertical',
+        main_pane_size: 60,
+        main_pane_min_width: 80,
+        agent_pane_min_width: 40, })
+
+        // when
+        manager = new TmuxSessionManager(ctx, config, mockTmuxDeps)
+      } finally {
+        if (previousOpenCodePort === undefined) {
+          delete process.env.OPENCODE_PORT
+        } else {
+          process.env.OPENCODE_PORT = previousOpenCodePort
+        }
+      }
+
+      // then
+      expect((manager as any).serverUrl).toBe('http://localhost:5678')
+    })
+
+    test('ignores invalid OPENCODE_PORT when serverUrl has port 0', async () => {
+      // given
+      const previousOpenCodePort = process.env.OPENCODE_PORT
+      process.env.OPENCODE_PORT = 'not-a-port'
+      let manager: TmuxSessionManagerType | undefined
+      try {
+        mockIsInsideTmux.mockReturnValue(true)
+        const { TmuxSessionManager } = await import('./manager')
+        const ctx = {
+          ...createMockContext(),
+          serverUrl: new URL('http://127.0.0.1:0/'),
+        }
+        const config = createTmuxConfig({ enabled: true,
+        layout: 'main-vertical',
+        main_pane_size: 60,
+        main_pane_min_width: 80,
+        agent_pane_min_width: 40, })
+
+        // when
+        manager = new TmuxSessionManager(ctx, config, mockTmuxDeps)
+      } finally {
+        if (previousOpenCodePort === undefined) {
+          delete process.env.OPENCODE_PORT
+        } else {
+          process.env.OPENCODE_PORT = previousOpenCodePort
+        }
+      }
 
       // then
       expect((manager as any).serverUrl).toBe('http://localhost:4096')
@@ -1989,7 +2064,7 @@ describe('TmuxSessionManager', () => {
       const cleanupPromise = manager.cleanup()
 
       // then
-      await expect(cleanupPromise).resolves.toBeUndefined()
+      expect(await cleanupPromise).toBeUndefined()
       expect(mockKillTmuxSessionIfExists).toHaveBeenCalledTimes(1)
     })
   })
diff --git a/src/features/tmux-subagent/manager.ts b/src/features/tmux-subagent/manager.ts
index 3340fb55d..353bdffec 100644
--- a/src/features/tmux-subagent/manager.ts
+++ b/src/features/tmux-subagent/manager.ts
@@ -72,7 +72,11 @@ export class TmuxSessionManager {
     this.client = ctx.client
     this.tmuxConfig = tmuxConfig
     this.deps = deps
-    const defaultPort = process.env.OPENCODE_PORT ?? "4096"
+    const configuredPort = process.env.OPENCODE_PORT
+    const parsedPort = configuredPort ? Number(configuredPort) : 4096
+    const defaultPort = Number.isInteger(parsedPort) && parsedPort > 0 && parsedPort <= 65535
+      ? String(parsedPort)
+      : "4096"
     const fallbackUrl = `http://localhost:${defaultPort}`
     const rawServerUrl = ctx.serverUrl?.toString()
     try {
diff --git a/src/hooks/auto-slash-command/executor-resolution.test.ts b/src/hooks/auto-slash-command/executor-resolution.test.ts
index 45c905467..82d924902 100644
--- a/src/hooks/auto-slash-command/executor-resolution.test.ts
+++ b/src/hooks/auto-slash-command/executor-resolution.test.ts
@@ -1,8 +1,9 @@
+/// <reference types="bun-types" />
+
 import { afterEach, describe, expect, it, spyOn } from "bun:test"
 import type { LoadedSkill } from "../../features/opencode-skill-loader"
 import * as shared from "../../shared"
-import * as slashcommand from "../../tools/slashcommand"
-import { executeSlashCommand } from "./executor"
+import * as slashcommand from "../../tools/slashcommand/command-discovery"
 
 let resolveCommandsInTextSpy: { mockRestore: () => void } | undefined
 let resolveFileReferencesInTextSpy: { mockRestore: () => void } | undefined
@@ -38,6 +39,11 @@ function restoreExecutorSpies(): void {
   discoverCommandsSyncSpy = undefined
 }
 
+async function executeSlashCommand(...args: Parameters<typeof import("./executor").executeSlashCommand>): ReturnType<typeof import("./executor").executeSlashCommand> {
+  const module = await import(`./executor?test=${Date.now()}-${Math.random()}`)
+  return module.executeSlashCommand(...args)
+}
+
 afterEach(restoreExecutorSpies)
 
 function createRestrictedSkill(): LoadedSkill {
diff --git a/src/hooks/auto-slash-command/executor.ts b/src/hooks/auto-slash-command/executor.ts
index eedd8881f..0b5c7ceb9 100644
--- a/src/hooks/auto-slash-command/executor.ts
+++ b/src/hooks/auto-slash-command/executor.ts
@@ -1,10 +1,8 @@
 import { dirname } from "path"
-import {
-  resolveCommandsInText,
-  resolveFileReferencesInText,
-} from "../../shared"
+import { resolveCommandsInText } from "../../shared/command-executor/resolve-commands-in-text"
+import { resolveFileReferencesInText } from "../../shared/file-reference-resolver"
 import { discoverAllSkills, type LoadedSkill, type LazyContentLoader } from "../../features/opencode-skill-loader"
-import { discoverCommandsSync } from "../../tools/slashcommand"
+import * as commandDiscovery from "../../tools/slashcommand/command-discovery"
 import type { CommandInfo as DiscoveredCommandInfo, CommandMetadata } from "../../tools/slashcommand/types"
 import type { ParsedSlashCommand } from "./types"
 
@@ -47,7 +45,7 @@ export interface ExecutorOptions {
 
 
 async function discoverAllCommands(options?: ExecutorOptions): Promise<CommandInfo[]> {
-  const discoveredCommands = discoverCommandsSync(options?.directory ?? process.cwd(), {
+  const discoveredCommands = commandDiscovery.discoverCommandsSync(options?.directory ?? process.cwd(), {
     pluginsEnabled: options?.pluginsEnabled,
     enabledPluginsOverride: options?.enabledPluginsOverride,
   })
diff --git a/src/tools/skill/tools.factory.test.ts b/src/tools/skill/tools.factory.test.ts
index 5b9a5ba30..b1e992607 100644
--- a/src/tools/skill/tools.factory.test.ts
+++ b/src/tools/skill/tools.factory.test.ts
@@ -4,13 +4,10 @@ import { afterEach, beforeEach, describe, expect, it, mock, spyOn } from "bun:te
 import type { ToolContext } from "@opencode-ai/plugin/tool"
 import type { LoadedSkill } from "../../features/opencode-skill-loader/types"
 import * as skillContent from "../../features/opencode-skill-loader/skill-content"
+import * as commandDiscovery from "../slashcommand/command-discovery"
 
 const discoverCommandsSync = mock(() => [])
 
-mock.module("../slashcommand/command-discovery", () => ({
-  discoverCommandsSync,
-}))
-
 function createMockSkill(name: string): LoadedSkill {
   return {
     name,
@@ -49,7 +46,13 @@ function createMockContext(sessionID: string): ToolContext {
   }
 }
 
+async function createSkillTool(...args: Parameters<typeof import("./tools").createSkillTool>): ReturnType<typeof import("./tools").createSkillTool> {
+  const module = await import(`./tools?test=${Date.now()}-${Math.random()}`)
+  return module.createSkillTool(...args)
+}
+
 beforeEach(() => {
+  spyOn(commandDiscovery, "discoverCommandsSync").mockImplementation(discoverCommandsSync)
   spyOn(skillContent, "getAllSkills").mockImplementation(getAllSkills)
   spyOn(skillContent, "clearSkillCache").mockImplementation(clearSkillCache)
 })
@@ -65,8 +68,7 @@ describe("createSkillTool", () => {
     const baselineDiscoverCommandsSyncCalls = discoverCommandsSync.mock.calls.length
 
     // when
-    const { createSkillTool } = await import("./tools")
-    const skillTool = createSkillTool({})
+    const skillTool = await createSkillTool({})
 
     // then
     expect(discoverCommandsSync.mock.calls.length).toBe(baselineDiscoverCommandsSyncCalls)
@@ -82,8 +84,7 @@ describe("createSkillTool", () => {
     const baselineGetAllSkillsCalls = getAllSkills.mock.calls.length
 
     // when
-    const { createSkillTool } = await import("./tools")
-    const skillTool = createSkillTool({})
+    const skillTool = await createSkillTool({})
 
     // then
     expect(getAllSkills.mock.calls.length).toBe(baselineGetAllSkillsCalls)
@@ -99,8 +100,7 @@ describe("createSkillTool", () => {
     const sessionContext = createMockContext("session-clear-once")
 
     // when
-    const { createSkillTool } = await import("./tools")
-    const skillTool = createSkillTool({})
+    const skillTool = await createSkillTool({})
     void skillTool.description
     await flushMicrotasks()
     await skillTool.execute({ name: "lazy-skill" }, sessionContext)
@@ -116,8 +116,7 @@ describe("createSkillTool", () => {
     const baselineGetAllSkillsCalls = getAllSkills.mock.calls.length
     const sessionAContext = createMockContext("session-a")
     const sessionBContext = createMockContext("session-b")
-    const { createSkillTool } = await import("./tools")
-    const skillTool = createSkillTool({})
+    const skillTool = await createSkillTool({})
 
     // when
     await skillTool.execute({ name: "lazy-skill" }, sessionAContext)
diff --git a/src/tools/skill/tools.ts b/src/tools/skill/tools.ts
index d49936f95..81bb14485 100644
--- a/src/tools/skill/tools.ts
+++ b/src/tools/skill/tools.ts
@@ -7,7 +7,7 @@ import type { SkillArgs, SkillLoadOptions } from "./types"
 import type { LoadedSkill } from "../../features/opencode-skill-loader"
 import { clearSkillCache, getAllSkills } from "../../features/opencode-skill-loader/skill-content"
 import { injectGitMasterConfig } from "../../features/opencode-skill-loader/skill-content"
-import { discoverCommandsSync } from "../slashcommand/command-discovery"
+import * as commandDiscovery from "../slashcommand/command-discovery"
 import type { CommandInfo } from "../slashcommand/types"
 import { formatLoadedCommand } from "../slashcommand/command-output-formatter"
 import { formatCombinedDescription } from "./description-formatter"
@@ -37,14 +37,7 @@ export function createSkillTool(options: SkillLoadOptions = {}): ToolDefinition
       disabledSkills: options?.disabledSkills,
       browserProvider: options?.browserProvider,
     })) ?? []
-    const allSkills = !options.skills
-      ? discovered
-      : [
-          ...discovered,
-          ...options.skills.filter(
-            (skill) => !new Set(discovered.map((discoveredSkill) => discoveredSkill.name)).has(skill.name)
-          ),
-        ]
+    const allSkills = options.skills ? [...options.skills] : discovered
 
     if (options.nativeSkills) {
       try {
@@ -58,7 +51,7 @@ export function createSkillTool(options: SkillLoadOptions = {}): ToolDefinition
   }
 
   const getCommands = (): CommandInfo[] => {
-    return discoverCommandsSync(undefined, {
+    return commandDiscovery.discoverCommandsSync(undefined, {
       pluginsEnabled: options.pluginsEnabled,
       enabledPluginsOverride: options.enabledPluginsOverride,
     }) ?? []
diff --git a/src/tools/slashcommand/command-discovery-deps.ts b/src/tools/slashcommand/command-discovery-deps.ts
new file mode 100644
index 000000000..5465e0dfc
--- /dev/null
+++ b/src/tools/slashcommand/command-discovery-deps.ts
@@ -0,0 +1,6 @@
+export { EXCLUDED_DIRS } from "../../shared/excluded-dirs"
+export { parseFrontmatter } from "../../shared/frontmatter"
+export { sanitizeModelField } from "../../shared/model-sanitizer"
+export { getOpenCodeCommandDirs } from "../../shared/opencode-command-dirs"
+export { discoverPluginCommandDefinitions } from "../../shared/plugin-command-discovery"
+export { findProjectOpencodeCommandDirs } from "../../shared/project-discovery-dirs"
diff --git a/src/tools/slashcommand/command-discovery.ts b/src/tools/slashcommand/command-discovery.ts
index 855f6dc28..0900dec42 100644
--- a/src/tools/slashcommand/command-discovery.ts
+++ b/src/tools/slashcommand/command-discovery.ts
@@ -7,11 +7,12 @@ import {
   getOpenCodeCommandDirs,
   discoverPluginCommandDefinitions,
   EXCLUDED_DIRS,
-} from "../../shared"
+} from "./command-discovery-deps"
 import type { CommandFrontmatter } from "../../features/claude-code-command-loader/types"
 import { isMarkdownFile } from "../../shared/file-utils"
-import { getClaudeConfigDir, log } from "../../shared"
-import { loadBuiltinCommands } from "../../features/builtin-commands"
+import { getClaudeConfigDir } from "../../shared/claude-config-dir"
+import { log } from "../../shared/logger"
+import { loadBuiltinCommands } from "../../features/builtin-commands/commands"
 import type { CommandInfo, CommandMetadata, CommandScope } from "./types"
 
 export interface CommandDiscoveryOptions {