diff --git a/src/plugin-handlers/agent-key-remapper.test.ts b/src/plugin-handlers/agent-key-remapper.test.ts
index 7640fbbf8..2153890c7 100644
--- a/src/plugin-handlers/agent-key-remapper.test.ts
+++ b/src/plugin-handlers/agent-key-remapper.test.ts
@@ -108,7 +108,7 @@ describe("remapAgentKeysToDisplayNames", () => {
     const agents = {
       sisyphus: { name: "sisyphus", prompt: "test", mode: "primary" },
       hephaestus: { name: "hephaestus", prompt: "test", mode: "primary" },
-      prometheus: { name: "prometheus", prompt: "test", mode: "all" },
+      prometheus: { name: "prometheus", prompt: "test", mode: "primary" },
       atlas: { name: "atlas", prompt: "test", mode: "primary" },
       oracle: { name: "oracle", prompt: "test", mode: "subagent" },
     }
@@ -136,7 +136,7 @@ describe("remapAgentKeysToDisplayNames", () => {
     expect(result[getAgentListDisplayName("prometheus")]).toEqual({
       name: getAgentRuntimeName("prometheus"),
       prompt: "test",
-      mode: "all",
+      mode: "primary",
     })
     expect(result[getAgentListDisplayName("atlas")]).toEqual({
       name: getAgentRuntimeName("atlas"),
@@ -151,7 +151,7 @@ describe("remapAgentKeysToDisplayNames", () => {
     const agents = {
       sisyphus: { prompt: "test", mode: "primary" },
       hephaestus: { prompt: "test", mode: "primary" },
-      prometheus: { prompt: "test", mode: "all" },
+      prometheus: { prompt: "test", mode: "primary" },
       atlas: { prompt: "test", mode: "primary" },
     }
 
@@ -172,7 +172,7 @@ describe("remapAgentKeysToDisplayNames", () => {
     expect(result[getAgentListDisplayName("prometheus")]).toEqual({
       name: getAgentRuntimeName("prometheus"),
       prompt: "test",
-      mode: "all",
+      mode: "primary",
     })
     expect(result[getAgentListDisplayName("atlas")]).toEqual({
       name: getAgentRuntimeName("atlas"),
diff --git a/src/plugin-handlers/agent-priority-order.test.ts b/src/plugin-handlers/agent-priority-order.test.ts
index 10890c3b0..d1af68a61 100644
--- a/src/plugin-handlers/agent-priority-order.test.ts
+++ b/src/plugin-handlers/agent-priority-order.test.ts
@@ -185,7 +185,7 @@ describe("agent-priority-order", () => {
         const agents: Record<string, unknown> = {
           [sisyphus]: { name: "sisyphus", mode: "primary" },
           [hephaestus]: { name: "hephaestus", mode: "primary" },
-          [prometheus]: { name: "prometheus", mode: "all" },
+          [prometheus]: { name: "prometheus", mode: "primary" },
           [atlas]: { name: "atlas", mode: "primary" },
         }
 
@@ -195,7 +195,7 @@ describe("agent-priority-order", () => {
         // then
         expect(result[sisyphus]).toEqual({ name: "sisyphus", mode: "primary", order: 1 })
         expect(result[hephaestus]).toEqual({ name: "hephaestus", mode: "primary", order: 2 })
-        expect(result[prometheus]).toEqual({ name: "prometheus", mode: "all", order: 3 })
+        expect(result[prometheus]).toEqual({ name: "prometheus", mode: "primary", order: 3 })
         expect(result[atlas]).toEqual({ name: "atlas", mode: "primary", order: 4 })
       })
 
diff --git a/src/plugin-handlers/config-handler.test.ts b/src/plugin-handlers/config-handler.test.ts
index e6ac62c9e..5e68eeede 100644
--- a/src/plugin-handlers/config-handler.test.ts
+++ b/src/plugin-handlers/config-handler.test.ts
@@ -447,7 +447,7 @@ describe("Plan agent demote behavior", () => {
     expect(agents.plan.prompt).toBe("original plan prompt")
   })
 
-  test("prometheus should have mode 'all' to be callable via task", async () => {
+  test("prometheus should have mode 'primary' like the other core agents", async () => {
     // given
     const pluginConfig = createPluginConfig({
       sisyphus_agent: {
@@ -474,7 +474,7 @@ describe("Plan agent demote behavior", () => {
     const agents = config.agent as Record<string, { mode?: string }>
     const prometheusKey = getAgentListDisplayName("prometheus")
     expect(agents[prometheusKey]).toBeDefined()
-    expect(agents[prometheusKey].mode).toBe("all")
+    expect(agents[prometheusKey].mode).toBe("primary")
   })
 })
 
@@ -1007,7 +1007,7 @@ describe("Plan agent model inheritance from prometheus", () => {
     spyOn(prometheusAgentConfigBuilder, "buildPrometheusAgentConfig").mockResolvedValue({
       model: "anthropic/claude-opus-4-6",
       variant: "max",
-      mode: "all",
+      mode: "primary",
       prompt: "prometheus prompt",
     })
     const pluginConfig = createPluginConfig({
diff --git a/src/plugin-handlers/plan-model-inheritance.test.ts b/src/plugin-handlers/plan-model-inheritance.test.ts
index 0c6cc77e8..58d0e68dd 100644
--- a/src/plugin-handlers/plan-model-inheritance.test.ts
+++ b/src/plugin-handlers/plan-model-inheritance.test.ts
@@ -20,7 +20,7 @@ describe("buildPlanDemoteConfig", () => {
       name: "prometheus",
       model: "anthropic/claude-opus-4-6",
       variant: "max",
-      mode: "all",
+      mode: "primary",
       prompt: "You are Prometheus...",
       permission: { edit: "allow" },
       description: "Plan agent (Prometheus)",
diff --git a/src/plugin-handlers/prometheus-agent-config-builder.test.ts b/src/plugin-handlers/prometheus-agent-config-builder.test.ts
index 90fe578fe..be19047f4 100644
--- a/src/plugin-handlers/prometheus-agent-config-builder.test.ts
+++ b/src/plugin-handlers/prometheus-agent-config-builder.test.ts
@@ -267,4 +267,19 @@ describe("buildPrometheusAgentConfig", () => {
         expect(result.model).toBe("anthropic/claude-opus-4-6");
       });
   });
+
+  test("returns Prometheus as a primary agent", async () => {
+    // given
+
+    // when
+    const result = await buildPrometheusAgentConfig({
+      configAgentPlan: undefined,
+      pluginPrometheusOverride: undefined,
+      userCategories: undefined,
+      currentModel: undefined,
+    });
+
+    // then
+    expect(result.mode).toBe("primary");
+  });
 });
diff --git a/src/plugin-handlers/prometheus-agent-config-builder.ts b/src/plugin-handlers/prometheus-agent-config-builder.ts
index 620e9d721..640847b94 100644
--- a/src/plugin-handlers/prometheus-agent-config-builder.ts
+++ b/src/plugin-handlers/prometheus-agent-config-builder.ts
@@ -97,7 +97,7 @@ export async function buildPrometheusAgentConfig(params: {
   const base: Record<string, unknown> = {
     ...(resolvedModel ? { model: resolvedModel } : {}),
     ...(variantToUse ? { variant: variantToUse } : {}),
-    mode: "all",
+    mode: "primary",
     prompt: getPrometheusPrompt(resolvedModel, params.disabledTools),
     permission: PROMETHEUS_PERMISSION,
     description: `${(params.configAgentPlan?.description as string) ?? "Plan agent"} (Prometheus - OhMyOpenCode)`,
diff --git a/src/tools/delegate-task/tools.test.ts b/src/tools/delegate-task/tools.test.ts
index 3e7c242b2..0508fc5cf 100644
--- a/src/tools/delegate-task/tools.test.ts
+++ b/src/tools/delegate-task/tools.test.ts
@@ -3657,11 +3657,11 @@ describe("sisyphus-task", () => {
       expect(result).toContain("plan-family")
     })
 
-    test("plan cannot delegate to prometheus (cross-blocking)", async () => {
+    test("plan cannot delegate to prometheus even when it is exposed as a primary agent", async () => {
       //#given
       const { createDelegateTask } = require("./tools")
       const mockClient = {
-         app: { agents: async () => ({ data: [{ name: "prometheus", mode: "subagent" }] }) },
+         app: { agents: async () => ({ data: [{ name: "prometheus", mode: "primary" }] }) },
          config: { get: async () => ({ data: { model: SYSTEM_DEFAULT_MODEL } }) },
          session: { get: async () => ({ data: { directory: "/project" } }), create: async () => ({ data: { id: "s" } }), prompt: async () => ({ data: {} }), promptAsync: async () => ({ data: {} }), messages: async () => ({ data: [] }), status: async () => ({ data: {} }) },
        }
@@ -4154,19 +4154,17 @@ describe("sisyphus-task", () => {
       expect(promptBody.tools.task).toBe(true)
     }, { timeout: 20000 })
 
-    test("prometheus subagent should have task permission as part of the plan family", async () => {
+    test("prometheus primary agent should not be callable via task", async () => {
       //#given
       const { createDelegateTask } = require("./tools")
-      let promptBody: any
-      const promptMock = async (input: any) => { promptBody = input.body; return { data: {} } }
        const mockClient = {
-         app: { agents: async () => ({ data: [{ name: "prometheus", mode: "subagent" }] }) },
+         app: { agents: async () => ({ data: [{ name: "prometheus", mode: "primary" }] }) },
          config: { get: async () => ({ data: { model: SYSTEM_DEFAULT_MODEL } }) },
          session: {
            get: async () => ({ data: { directory: "/project" } }),
            create: async () => ({ data: { id: "ses_prometheus_task" } }),
-           prompt: promptMock,
-           promptAsync: promptMock,
+           prompt: async () => ({ data: {} }),
+           promptAsync: async () => ({ data: {} }),
            messages: async () => ({ data: [{ info: { role: "assistant" }, parts: [{ type: "text", text: "Plan created" }] }] }),
            status: async () => ({ data: { "ses_prometheus_task": { type: "idle" } } }),
          },
@@ -4174,13 +4172,13 @@ describe("sisyphus-task", () => {
        const tool = createDelegateTask({ manager: { launch: async () => ({}) }, client: mockClient })
       
       //#when
-      await tool.execute(
+      const result = await tool.execute(
         { description: "Test prometheus task permission", prompt: "Create a plan", subagent_type: "prometheus", run_in_background: false, load_skills: [] },
         { sessionID: "p", messageID: "m", agent: "sisyphus", abort: new AbortController().signal }
       )
       
-      //#then - prometheus shares task permission with the plan family
-      expect(promptBody.tools.task).toBe(true)
+      //#then
+      expect(result).toContain('Unknown agent: "prometheus"')
     }, { timeout: 20000 })
 
     test("non-plan subagent should NOT have task permission", async () => {