refactor(athena): rename session_handoff to switch_agent to avoid confusion with /handoff command

Rename across all layers to eliminate naming ambiguity:
- Tool: session_handoff → switch_agent
- Hook: agent-handoff → agent-switch
- Feature: agent-handoff/ → agent-switch/
- Types: SessionHandoffArgs → SwitchAgentArgs, PendingHandoff → PendingSwitch
- Functions: setPendingHandoff → setPendingSwitch, consumePendingHandoff → consumePendingSwitch

/handoff = inter-session context summary (existing command)
switch_agent = intra-session active agent change (our new tool)

src/agents/athena/agent.ts

@@ -96,11 +96,11 @@ Question({
 })
 
 Step 6: After the user selects an action:
-- **"Fix now (Atlas)"** → Call session_handoff with agent="atlas" and context containing the confirmed findings summary, the original question, and instruction to implement the fixes.
-- **"Create plan (Prometheus)"** → Call session_handoff with agent="prometheus" and context containing the confirmed findings summary, the original question, and instruction to create a phased plan.
+- **"Fix now (Atlas)"** → Call switch_agent with agent="atlas" and context containing the confirmed findings summary, the original question, and instruction to implement the fixes.
+- **"Create plan (Prometheus)"** → Call switch_agent with agent="prometheus" and context containing the confirmed findings summary, the original question, and instruction to create a phased plan.
 - **"No action"** → Acknowledge and end. Do not delegate.
 
-The session_handoff tool switches the active agent. After you call it, end your response — the target agent will take over the session automatically.
+The switch_agent tool switches the active agent. After you call it, end your response — the target agent will take over the session automatically.
 
 ## Constraints
 - Use the Question tool for member selection BEFORE calling athena_council (unless user pre-specified).

src/config/schema/hooks.ts

@@ -49,7 +49,7 @@ export const HookNameSchema = z.enum([
   "write-existing-file-guard",
   "anthropic-effort",
   "hashline-read-enhancer",
-  "agent-handoff",
+  "agent-switch",
 ])
 
 export type HookName = z.infer<typeof HookNameSchema>

src/features/agent-handoff/index.ts

@@ -1,2 +0,0 @@
-export { setPendingHandoff, consumePendingHandoff, _resetForTesting } from "./state"
-export type { PendingHandoff } from "./state"

src/features/agent-handoff/state.test.ts

@@ -1,50 +0,0 @@
-import { describe, test, expect, beforeEach } from "bun:test"
-import { setPendingHandoff, consumePendingHandoff, _resetForTesting } from "./state"
-
-describe("agent-handoff state", () => {
-  beforeEach(() => {
-    _resetForTesting()
-  })
-
-  //#given a pending handoff is set
-  //#when consumePendingHandoff is called
-  //#then it returns the handoff and removes it
-  test("should store and consume a pending handoff", () => {
-    setPendingHandoff("session-1", "atlas", "Fix these findings")
-
-    const handoff = consumePendingHandoff("session-1")
-
-    expect(handoff).toEqual({ agent: "atlas", context: "Fix these findings" })
-    expect(consumePendingHandoff("session-1")).toBeUndefined()
-  })
-
-  //#given no pending handoff exists
-  //#when consumePendingHandoff is called
-  //#then it returns undefined
-  test("should return undefined when no handoff is pending", () => {
-    expect(consumePendingHandoff("session-1")).toBeUndefined()
-  })
-
-  //#given a pending handoff is set
-  //#when a new handoff is set for the same session
-  //#then the latest handoff wins
-  test("should overwrite previous handoff for same session", () => {
-    setPendingHandoff("session-1", "atlas", "Fix A")
-    setPendingHandoff("session-1", "prometheus", "Plan B")
-
-    const handoff = consumePendingHandoff("session-1")
-
-    expect(handoff).toEqual({ agent: "prometheus", context: "Plan B" })
-  })
-
-  //#given handoffs for different sessions
-  //#when consumed separately
-  //#then each session gets its own handoff
-  test("should isolate handoffs by session", () => {
-    setPendingHandoff("session-1", "atlas", "Fix A")
-    setPendingHandoff("session-2", "prometheus", "Plan B")
-
-    expect(consumePendingHandoff("session-1")).toEqual({ agent: "atlas", context: "Fix A" })
-    expect(consumePendingHandoff("session-2")).toEqual({ agent: "prometheus", context: "Plan B" })
-  })
-})

src/features/agent-handoff/state.ts

@@ -1,23 +0,0 @@
-export interface PendingHandoff {
-  agent: string
-  context: string
-}
-
-const pendingHandoffs = new Map<string, PendingHandoff>()
-
-export function setPendingHandoff(sessionID: string, agent: string, context: string): void {
-  pendingHandoffs.set(sessionID, { agent, context })
-}
-
-export function consumePendingHandoff(sessionID: string): PendingHandoff | undefined {
-  const handoff = pendingHandoffs.get(sessionID)
-  if (handoff) {
-    pendingHandoffs.delete(sessionID)
-  }
-  return handoff
-}
-
-/** @internal For testing only */
-export function _resetForTesting(): void {
-  pendingHandoffs.clear()
-}

src/features/agent-switch/index.ts

@@ -0,0 +1,2 @@
+export { setPendingSwitch, consumePendingSwitch, _resetForTesting } from "./state"
+export type { PendingSwitch } from "./state"

src/features/agent-switch/state.test.ts

@@ -0,0 +1,50 @@
+import { describe, test, expect, beforeEach } from "bun:test"
+import { setPendingSwitch, consumePendingSwitch, _resetForTesting } from "./state"
+
+describe("agent-switch state", () => {
+  beforeEach(() => {
+    _resetForTesting()
+  })
+
+  //#given a pending switch is set
+  //#when consumePendingSwitch is called
+  //#then it returns the switch and removes it
+  test("should store and consume a pending switch", () => {
+    setPendingSwitch("session-1", "atlas", "Fix these findings")
+
+    const entry = consumePendingSwitch("session-1")
+
+    expect(entry).toEqual({ agent: "atlas", context: "Fix these findings" })
+    expect(consumePendingSwitch("session-1")).toBeUndefined()
+  })
+
+  //#given no pending switch exists
+  //#when consumePendingSwitch is called
+  //#then it returns undefined
+  test("should return undefined when no switch is pending", () => {
+    expect(consumePendingSwitch("session-1")).toBeUndefined()
+  })
+
+  //#given a pending switch is set
+  //#when a new switch is set for the same session
+  //#then the latest switch wins
+  test("should overwrite previous switch for same session", () => {
+    setPendingSwitch("session-1", "atlas", "Fix A")
+    setPendingSwitch("session-1", "prometheus", "Plan B")
+
+    const entry = consumePendingSwitch("session-1")
+
+    expect(entry).toEqual({ agent: "prometheus", context: "Plan B" })
+  })
+
+  //#given switches for different sessions
+  //#when consumed separately
+  //#then each session gets its own switch
+  test("should isolate switches by session", () => {
+    setPendingSwitch("session-1", "atlas", "Fix A")
+    setPendingSwitch("session-2", "prometheus", "Plan B")
+
+    expect(consumePendingSwitch("session-1")).toEqual({ agent: "atlas", context: "Fix A" })
+    expect(consumePendingSwitch("session-2")).toEqual({ agent: "prometheus", context: "Plan B" })
+  })
+})

src/features/agent-switch/state.ts

@@ -0,0 +1,23 @@
+export interface PendingSwitch {
+  agent: string
+  context: string
+}
+
+const pendingSwitches = new Map<string, PendingSwitch>()
+
+export function setPendingSwitch(sessionID: string, agent: string, context: string): void {
+  pendingSwitches.set(sessionID, { agent, context })
+}
+
+export function consumePendingSwitch(sessionID: string): PendingSwitch | undefined {
+  const entry = pendingSwitches.get(sessionID)
+  if (entry) {
+    pendingSwitches.delete(sessionID)
+  }
+  return entry
+}
+
+/** @internal For testing only */
+export function _resetForTesting(): void {
+  pendingSwitches.clear()
+}

src/hooks/agent-handoff/index.ts

@@ -1 +0,0 @@
-export { createAgentHandoffHook } from "./hook"

src/hooks/agent-switch/hook.ts

@@ -1,10 +1,10 @@
 import type { PluginInput } from "@opencode-ai/plugin"
-import { consumePendingHandoff } from "../../features/agent-handoff"
+import { consumePendingSwitch } from "../../features/agent-switch"
 import { log } from "../../shared/logger"
 
-const HOOK_NAME = "agent-handoff" as const
+const HOOK_NAME = "agent-switch" as const
 
-export function createAgentHandoffHook(ctx: PluginInput) {
+export function createAgentSwitchHook(ctx: PluginInput) {
   return {
     event: async (input: { event: { type: string; properties?: Record<string, unknown> } }): Promise<void> => {
       if (input.event.type !== "session.idle") return
@@ -13,24 +13,24 @@ export function createAgentHandoffHook(ctx: PluginInput) {
       const sessionID = props?.sessionID as string | undefined
       if (!sessionID) return
 
-      const handoff = consumePendingHandoff(sessionID)
-      if (!handoff) return
+      const pending = consumePendingSwitch(sessionID)
+      if (!pending) return
 
-      log(`[${HOOK_NAME}] Executing handoff to ${handoff.agent}`, { sessionID })
+      log(`[${HOOK_NAME}] Switching to ${pending.agent}`, { sessionID })
 
       try {
         await ctx.client.session.promptAsync({
           path: { id: sessionID },
           body: {
-            agent: handoff.agent,
-            parts: [{ type: "text", text: handoff.context }],
+            agent: pending.agent,
+            parts: [{ type: "text", text: pending.context }],
           },
           query: { directory: ctx.directory },
         })
 
-        log(`[${HOOK_NAME}] Handoff to ${handoff.agent} complete`, { sessionID })
+        log(`[${HOOK_NAME}] Switch to ${pending.agent} complete`, { sessionID })
       } catch (err) {
-        log(`[${HOOK_NAME}] Handoff failed`, { sessionID, error: String(err) })
+        log(`[${HOOK_NAME}] Switch failed`, { sessionID, error: String(err) })
       }
     },
   }

src/hooks/agent-switch/index.ts

@@ -0,0 +1 @@
+export { createAgentSwitchHook } from "./hook"

src/hooks/index.ts

@@ -51,4 +51,4 @@ export { createWriteExistingFileGuardHook } from "./write-existing-file-guard";
 export { createHashlineReadEnhancerHook } from "./hashline-read-enhancer";
 export { createJsonErrorRecoveryHook, JSON_ERROR_TOOL_EXCLUDE_LIST, JSON_ERROR_PATTERNS, JSON_ERROR_REMINDER } from "./json-error-recovery";
 export { createHashlineEditDiffEnhancerHook } from "./hashline-edit-diff-enhancer";
-export { createAgentHandoffHook } from "./agent-handoff";
+export { createAgentSwitchHook } from "./agent-switch";

src/plugin/event.ts

@@ -156,7 +156,7 @@ export function createEventHandler(args: {
     await Promise.resolve(hooks.compactionTodoPreserver?.event?.(input));
     await Promise.resolve(hooks.writeExistingFileGuard?.event?.(input));
     await Promise.resolve(hooks.atlasHook?.handler?.(input));
-    await Promise.resolve(hooks.agentHandoffHook?.event?.(input));
+    await Promise.resolve(hooks.agentSwitchHook?.event?.(input));
   };
 
   const recentSyntheticIdles = new Map<string, number>();

src/plugin/hooks/create-continuation-hooks.ts

@@ -9,7 +9,7 @@ import {
   createCompactionContextInjector,
   createCompactionTodoPreserverHook,
   createAtlasHook,
-  createAgentHandoffHook,
+  createAgentSwitchHook,
 } from "../../hooks"
 import { safeCreateHook } from "../../shared/safe-create-hook"
 import { createUnstableAgentBabysitter } from "../unstable-agent-babysitter"
@@ -22,7 +22,7 @@ export type ContinuationHooks = {
   unstableAgentBabysitter: ReturnType<typeof createUnstableAgentBabysitter> | null
   backgroundNotificationHook: ReturnType<typeof createBackgroundNotificationHook> | null
   atlasHook: ReturnType<typeof createAtlasHook> | null
-  agentHandoffHook: ReturnType<typeof createAgentHandoffHook> | null
+  agentSwitchHook: ReturnType<typeof createAgentSwitchHook> | null
 }
 
 type SessionRecovery = {
@@ -113,8 +113,8 @@ export function createContinuationHooks(args: {
         }))
     : null
 
-  const agentHandoffHook = isHookEnabled("agent-handoff")
-    ? safeHook("agent-handoff", () => createAgentHandoffHook(ctx))
+  const agentSwitchHook = isHookEnabled("agent-switch")
+    ? safeHook("agent-switch", () => createAgentSwitchHook(ctx))
     : null
 
   return {
@@ -125,6 +125,6 @@ export function createContinuationHooks(args: {
     unstableAgentBabysitter,
     backgroundNotificationHook,
     atlasHook,
-    agentHandoffHook,
+    agentSwitchHook,
   }
 }

src/plugin/tool-registry.ts

@@ -11,7 +11,7 @@ import {
   createBackgroundTools,
   createCallOmoAgent,
   createAthenaCouncilTool,
-  createSessionHandoffTool,
+  createSwitchAgentTool,
   createLookAt,
   createSkillMcpTool,
   createSkillTool,
@@ -134,7 +134,7 @@ export function createToolRegistry(args: {
     ...backgroundTools,
     call_omo_agent: callOmoAgent,
     athena_council: athenaCouncilTool,
-    session_handoff: createSessionHandoffTool(),
+    switch_agent: createSwitchAgentTool(),
     ...(lookAt ? { look_at: lookAt } : {}),
     task: delegateTask,
     skill_mcp: skillMcpTool,

src/tools/index.ts

@@ -38,7 +38,7 @@ export { createCallOmoAgent } from "./call-omo-agent"
 export { createAthenaCouncilTool } from "./athena-council"
 export { createLookAt } from "./look-at"
 export { createDelegateTask } from "./delegate-task"
-export { createSessionHandoffTool } from "./session-handoff"
+export { createSwitchAgentTool } from "./switch-agent"
 export {
   createTaskCreateTool,
   createTaskGetTool,

src/tools/session-handoff/index.ts

@@ -1 +0,0 @@
-export { createSessionHandoffTool } from "./tools"

src/tools/session-handoff/types.ts

@@ -1,4 +0,0 @@
-export interface SessionHandoffArgs {
-  agent: string
-  context: string
-}

src/tools/switch-agent/index.ts

@@ -0,0 +1 @@
+export { createSwitchAgentTool } from "./tools"

src/tools/switch-agent/tools.test.ts

@@ -1,9 +1,9 @@
 import { describe, test, expect, beforeEach } from "bun:test"
-import { createSessionHandoffTool } from "./tools"
-import { consumePendingHandoff, _resetForTesting as resetHandoff } from "../../features/agent-handoff"
+import { createSwitchAgentTool } from "./tools"
+import { consumePendingSwitch, _resetForTesting as resetSwitch } from "../../features/agent-switch"
 import { getSessionAgent, _resetForTesting as resetSession } from "../../features/claude-code-session-state"
 
-describe("session_handoff tool", () => {
+describe("switch_agent tool", () => {
   const sessionID = "test-session-123"
   const messageID = "msg-456"
   const agent = "athena"
@@ -16,25 +16,25 @@ describe("session_handoff tool", () => {
   }
 
   beforeEach(() => {
-    resetHandoff()
+    resetSwitch()
     resetSession()
   })
 
-  //#given valid atlas handoff args
+  //#given valid atlas switch args
   //#when execute is called
-  //#then it stores pending handoff and updates session agent
-  test("should queue handoff to atlas", async () => {
-    const tool = createSessionHandoffTool()
+  //#then it stores pending switch and updates session agent
+  test("should queue switch to atlas", async () => {
+    const tool = createSwitchAgentTool()
     const result = await tool.execute(
       { agent: "atlas", context: "Fix the auth bug based on council findings" },
       toolContext
     )
 
     expect(result).toContain("atlas")
-    expect(result).toContain("Handoff queued")
+    expect(result).toContain("switch")
 
-    const handoff = consumePendingHandoff(sessionID)
-    expect(handoff).toEqual({
+    const entry = consumePendingSwitch(sessionID)
+    expect(entry).toEqual({
       agent: "atlas",
       context: "Fix the auth bug based on council findings",
     })
@@ -42,50 +42,50 @@ describe("session_handoff tool", () => {
     expect(getSessionAgent(sessionID)).toBe("atlas")
   })
 
-  //#given valid prometheus handoff args
+  //#given valid prometheus switch args
   //#when execute is called
-  //#then it stores pending handoff for prometheus
-  test("should queue handoff to prometheus", async () => {
-    const tool = createSessionHandoffTool()
+  //#then it stores pending switch for prometheus
+  test("should queue switch to prometheus", async () => {
+    const tool = createSwitchAgentTool()
     const result = await tool.execute(
       { agent: "Prometheus", context: "Create a plan for the refactoring" },
       toolContext
     )
 
     expect(result).toContain("prometheus")
-    expect(result).toContain("Handoff queued")
+    expect(result).toContain("switch")
 
-    const handoff = consumePendingHandoff(sessionID)
-    expect(handoff?.agent).toBe("prometheus")
+    const entry = consumePendingSwitch(sessionID)
+    expect(entry?.agent).toBe("prometheus")
   })
 
   //#given an invalid agent name
   //#when execute is called
   //#then it returns an error
   test("should reject invalid agent names", async () => {
-    const tool = createSessionHandoffTool()
+    const tool = createSwitchAgentTool()
     const result = await tool.execute(
       { agent: "librarian", context: "Some context" },
       toolContext
     )
 
-    expect(result).toContain("Invalid handoff target")
+    expect(result).toContain("Invalid switch target")
     expect(result).toContain("librarian")
-    expect(consumePendingHandoff(sessionID)).toBeUndefined()
+    expect(consumePendingSwitch(sessionID)).toBeUndefined()
   })
 
   //#given agent name with different casing
   //#when execute is called
   //#then it normalizes to lowercase
   test("should handle case-insensitive agent names", async () => {
-    const tool = createSessionHandoffTool()
+    const tool = createSwitchAgentTool()
     await tool.execute(
       { agent: "ATLAS", context: "Fix things" },
       toolContext
     )
 
-    const handoff = consumePendingHandoff(sessionID)
-    expect(handoff?.agent).toBe("atlas")
+    const entry = consumePendingSwitch(sessionID)
+    expect(entry?.agent).toBe("atlas")
     expect(getSessionAgent(sessionID)).toBe("atlas")
   })
 })

src/tools/switch-agent/tools.ts

@@ -1,37 +1,37 @@
 import { tool, type ToolDefinition } from "@opencode-ai/plugin"
-import { setPendingHandoff } from "../../features/agent-handoff"
+import { setPendingSwitch } from "../../features/agent-switch"
 import { updateSessionAgent } from "../../features/claude-code-session-state"
-import type { SessionHandoffArgs } from "./types"
+import type { SwitchAgentArgs } from "./types"
 
 const DESCRIPTION =
   "Switch the active session agent. After calling this tool, the session will transition to the specified agent " +
-  "with the provided context as its starting prompt. Use this to hand off work to another agent " +
-  "(e.g., Atlas for fixes, Prometheus for planning). The handoff executes when the current agent's turn completes."
+  "with the provided context as its starting prompt. Use this to route work to another agent " +
+  "(e.g., Atlas for fixes, Prometheus for planning). The switch executes when the current agent's turn completes."
 
 const ALLOWED_AGENTS = new Set(["atlas", "prometheus", "sisyphus", "hephaestus"])
 
-export function createSessionHandoffTool(): ToolDefinition {
+export function createSwitchAgentTool(): ToolDefinition {
   return tool({
     description: DESCRIPTION,
     args: {
       agent: tool.schema
         .string()
-        .describe("Target agent name to hand off to (e.g., 'atlas', 'prometheus')"),
+        .describe("Target agent name to switch to (e.g., 'atlas', 'prometheus')"),
       context: tool.schema
         .string()
         .describe("Context message for the target agent — include confirmed findings, the original question, and what action to take"),
     },
-    async execute(args: SessionHandoffArgs, toolContext) {
+    async execute(args: SwitchAgentArgs, toolContext) {
       const agentName = args.agent.toLowerCase()
 
       if (!ALLOWED_AGENTS.has(agentName)) {
-        return `Invalid handoff target: "${args.agent}". Allowed agents: ${[...ALLOWED_AGENTS].join(", ")}`
+        return `Invalid switch target: "${args.agent}". Allowed agents: ${[...ALLOWED_AGENTS].join(", ")}`
       }
 
       updateSessionAgent(toolContext.sessionID, agentName)
-      setPendingHandoff(toolContext.sessionID, agentName, args.context)
+      setPendingSwitch(toolContext.sessionID, agentName, args.context)
 
-      return `Handoff queued. Session will switch to ${agentName} when your turn completes.`
+      return `Agent switch queued. Session will switch to ${agentName} when your turn completes.`
     },
   })
 }

src/tools/switch-agent/types.ts

@@ -0,0 +1,4 @@
+export interface SwitchAgentArgs {
+  agent: string
+  context: string
+}