diff --git a/src/plugin-handlers/tool-config-handler-task-deny.test.ts b/src/plugin-handlers/tool-config-handler-task-deny.test.ts
new file mode 100644
index 000000000..8ce3d6bc7
--- /dev/null
+++ b/src/plugin-handlers/tool-config-handler-task-deny.test.ts
@@ -0,0 +1,100 @@
+/// <reference types="bun-types" />
+
+import { describe, expect, it } from "bun:test"
+import type { OhMyOpenCodeConfig } from "../config"
+import { OhMyOpenCodeConfigSchema } from "../config"
+import { applyToolConfig } from "./tool-config-handler"
+
+type TestAgent = {
+  permission?: Record<string, unknown>
+}
+
+const TASK_DENIED_SUBAGENTS = [
+  "librarian",
+  "explore",
+  "oracle",
+  "multimodal-looker",
+  "metis",
+  "momus",
+] as const
+
+const TASK_ALLOWED_AGENT_NAMES = [
+  "sisyphus",
+  "atlas",
+  "hephaestus",
+  "sisyphus-junior",
+] as const
+
+function createParams(agentNames: readonly string[]): {
+  readonly config: Record<string, unknown>
+  readonly pluginConfig: OhMyOpenCodeConfig
+  readonly agentResult: Record<string, TestAgent>
+} {
+  const agentResult: Record<string, TestAgent> = {}
+  for (const agentName of agentNames) {
+    agentResult[agentName] = { permission: {} }
+  }
+
+  return {
+    config: { tools: {}, permission: {} },
+    pluginConfig: OhMyOpenCodeConfigSchema.parse({}),
+    agentResult,
+  }
+}
+
+function requirePermission(
+  agentResult: Record<string, TestAgent>,
+  agentName: string,
+): Record<string, unknown> {
+  const permission = agentResult[agentName]?.permission
+  if (!permission) {
+    throw new Error(`Missing permission for ${agentName}`)
+  }
+  return permission
+}
+
+describe("applyToolConfig task permission hard denials", () => {
+  describe("#given read-only and specialist subagents", () => {
+    describe("#when applying tool config", () => {
+      for (const agentName of TASK_DENIED_SUBAGENTS) {
+        it(`#then should explicitly deny task for ${agentName}`, () => {
+          const params = createParams([agentName])
+
+          applyToolConfig(params)
+
+          const permission = requirePermission(params.agentResult, agentName)
+          expect(permission.task).toBe("deny")
+        })
+      }
+    })
+  })
+
+  describe("#given librarian search permissions", () => {
+    describe("#when applying tool config", () => {
+      it("#then should keep grep_app allowed while task is denied", () => {
+        const params = createParams(["librarian"])
+
+        applyToolConfig(params)
+
+        const permission = requirePermission(params.agentResult, "librarian")
+        expect(permission["grep_app_*"]).toBe("allow")
+        expect(permission.task).toBe("deny")
+      })
+    })
+  })
+
+  describe("#given primary and executor agents", () => {
+    describe("#when applying tool config", () => {
+      for (const agentName of TASK_ALLOWED_AGENT_NAMES) {
+        it(`#then should keep task allowed for ${agentName}`, () => {
+          const params = createParams([agentName])
+
+          applyToolConfig(params)
+
+          const permission = requirePermission(params.agentResult, agentName)
+          expect(permission.task).toBe("allow")
+        })
+      }
+    })
+  })
+})
diff --git a/src/plugin-handlers/tool-config-handler.ts b/src/plugin-handlers/tool-config-handler.ts
index f1139f75f..bf07b2261 100644
--- a/src/plugin-handlers/tool-config-handler.ts
+++ b/src/plugin-handlers/tool-config-handler.ts
@@ -4,6 +4,15 @@ import { isTaskSystemEnabled } from "../shared";
 
 type AgentWithPermission = { permission?: Record<string, unknown> };
 
+const TASK_DENIED_SUBAGENT_KEYS = [
+  "librarian",
+  "explore",
+  "oracle",
+  "multimodal-looker",
+  "metis",
+  "momus",
+] as const;
+
 function getConfigQuestionPermission(): string | null {
   const configContent = process.env.OPENCODE_CONFIG_CONTENT;
   if (!configContent) return null;
@@ -21,6 +30,12 @@ function agentByKey(agentResult: Record<string, unknown>, key: string): AgentWit
     | undefined;
 }
 
+function denyTaskForAgent(agentResult: Record<string, unknown>, key: string): void {
+  const agent = agentByKey(agentResult, key);
+  if (!agent) return;
+  agent.permission = { ...agent.permission, task: "deny" };
+}
+
 export function applyToolConfig(params: {
   config: Record<string, unknown>;
   pluginConfig: OhMyOpenCodeConfig;
@@ -59,6 +74,10 @@ export function applyToolConfig(params: {
     isCliRunMode ? "deny" :
     "allow";
 
+  for (const agentKey of TASK_DENIED_SUBAGENT_KEYS) {
+    denyTaskForAgent(params.agentResult, agentKey);
+  }
+
   const librarian = agentByKey(params.agentResult, "librarian");
   if (librarian) {
     librarian.permission = { ...librarian.permission, "grep_app_*": "allow" };