diff --git a/packages/sdk/src/core/agent-loop.integration.test.ts b/packages/sdk/src/core/agent-loop.integration.test.ts
index 4a50dd55..eb83a897 100644
--- a/packages/sdk/src/core/agent-loop.integration.test.ts
+++ b/packages/sdk/src/core/agent-loop.integration.test.ts
@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'bun:test'
 import z from 'zod/v4'
+import type { DebounceContext } from '~/core/agents/debounce.js'
 import { agentEvents } from '~/core/agents/state.js'
 import { MockLLMProvider } from '~/core/llm/mock.js'
 import { ModelId } from '~/core/llm/schema.js'
@@ -209,6 +210,82 @@ describe('agent processing loop', () => {
 
 			await harness.shutdown()
 		})
+
+		const createCallIdPreset = (seen: string[]): Preset => ({
+			id: 'test',
+			name: 'Test Preset',
+			orchestrator: {
+				system: 'You are a test agent.',
+				model: ModelId('mock'),
+				tools: [
+					createTool({
+						name: 'record_call_id',
+						description: 'Records the call id it runs under',
+						input: z.unknown(),
+						execute: async (_input, context) => {
+							seen.push(context.toolCallId)
+							return { ok: true, value: 'recorded' }
+						},
+					}),
+				],
+				agents: [],
+				debounceMs: 0,
+			},
+			agents: [],
+		})
+
+		it('tool context carries the id of the call being executed', async () => {
+			const seen: string[] = []
+			const harness = new TestHarness({
+				presets: [createCallIdPreset(seen)],
+				llmProvider: MockLLMProvider.withSequence([
+					{
+						toolCalls: [
+							{ id: ToolCallId('tc1'), name: 'record_call_id', input: {} },
+							{ id: ToolCallId('tc2'), name: 'record_call_id', input: {} },
+						],
+					},
+					{ content: 'Done', toolCalls: [] },
+				]),
+			})
+
+			const session = await harness.createSession('test')
+			await session.sendAndWaitForIdle('Record')
+
+			expect(seen).toEqual(['tc1', 'tc2'])
+
+			await harness.shutdown()
+		})
+
+		it('debounce callback sees a user message that is not in the mailbox', async () => {
+			const contexts: DebounceContext[] = []
+			const preset: Preset = {
+				id: 'test',
+				name: 'Test Preset',
+				orchestrator: {
+					system: 'You are a test agent.',
+					model: ModelId('mock'),
+					tools: [],
+					agents: [],
+					debounceCallback: (context) => {
+						contexts.push(context)
+						return 'process_now'
+					},
+				},
+				agents: [],
+			}
+			const harness = new TestHarness({
+				presets: [preset],
+				llmProvider: MockLLMProvider.withFixedResponse({ content: 'Hello back!', toolCalls: [] }),
+			})
+
+			const session = await harness.createSession('test')
+			await session.sendAndWaitForIdle('Hello')
+
+			expect(contexts.some((c) => c.hasPendingInput && c.totalPending === 0)).toBe(true)
+
+			await harness.shutdown()
+		})
 	})
 
 	// =========================================================================
diff --git a/packages/sdk/src/core/agents/agent-config.test.ts b/packages/sdk/src/core/agents/agent-config.test.ts
index 8117f2cd..ea28e4f0 100644
--- a/packages/sdk/src/core/agents/agent-config.test.ts
+++ b/packages/sdk/src/core/agents/agent-config.test.ts
@@ -40,6 +40,7 @@ describe('Debounce Callbacks', () => {
 		oldestWaitingMs,
 		totalPending: messageCount,
 		pendingToolResults,
+		hasPendingInput: messageCount > 0,
 	})
 
 	describe('defaultDebounceCallback', () => {
@@ -140,6 +141,11 @@ describe('Debounce Callbacks', () => {
 			expect(waitForResponseDebounceCallback(context)).toBe('wait')
 		})
 
+		test("returns 'process_now' for input outside the mailbox, such as a user chat message", () => {
+			const context = { ...createContext(0, 0, [createToolResult('send_message', 1000)]), hasPendingInput: true }
+			expect(waitForResponseDebounceCallback(context)).toBe('process_now')
+		})
+
 		test("returns 'wait' for start_* agent tool", () => {
 			const context = createContext(0, 0, [
 				createToolResult('start_researcher', 1000),
@@ -225,6 +231,7 @@ describe('Debounce Callbacks', () => {
 				messages: [],
 				oldestWaitingMs: 0,
 				totalPending: 0,
+				hasPendingInput: false,
 				pendingToolResults: [
 					{ toolCallId: ToolCallId('tc-1'), toolName: 'send_message', timestamp: now - 59000, isError: false, content: '' },
 					{ toolCallId: ToolCallId('tc-2'), toolName: 'send_message', timestamp: now - 30000, isError: false, content: '' },
diff --git a/packages/sdk/src/core/agents/agent.ts b/packages/sdk/src/core/agents/agent.ts
index 3f267fd3..334afb8b 100644
--- a/packages/sdk/src/core/agents/agent.ts
+++ b/packages/sdk/src/core/agents/agent.ts
@@ -453,8 +453,10 @@ export class Agent {
 			const unconsumed = getUnconsumedMessages(sessionState, this.id)
 			const pendingToolResults = currentState.pendingToolResults
 
+			const hasPendingInput = this.hasPluginPendingMessages()
+
 			// If no messages, no pending tool results, and no plugin pending, nothing to do
-			if (unconsumed.length === 0 && pendingToolResults.length === 0 && !this.hasPluginPendingMessages()) {
+			if (unconsumed.length === 0 && pendingToolResults.length === 0 && !hasPendingInput) {
 				this.cancelSchedule()
 				return
 			}
@@ -469,6 +471,7 @@ export class Agent {
 				oldestWaitingMs,
 				totalPending: unconsumed.length,
 				pendingToolResults,
+				hasPendingInput,
 			})
 
 			// Re-check after async callback — schedule could be cancelled during await
@@ -1099,6 +1102,7 @@ export class Agent {
 		const context: ToolContext = {
 			...this.buildAgentContext(agentState),
 			logger: this.logger.child({ toolName: toolCall.name }),
+			toolCallId: effectiveToolCall.id,
 		}
 
 		const result = await this.toolExecutor.execute(tool, effectiveToolCall.input, context)
diff --git a/packages/sdk/src/core/agents/debounce.ts b/packages/sdk/src/core/agents/debounce.ts
index 5e42794f..24f7d04e 100644
--- a/packages/sdk/src/core/agents/debounce.ts
+++ b/packages/sdk/src/core/agents/debounce.ts
@@ -13,6 +13,8 @@ export interface DebounceContext {
 	totalPending: number
 	/** Pending tool results awaiting LLM processing */
 	pendingToolResults: PendingToolResult[]
+	/** Whether any dequeue source holds input for this agent. `messages` is the mailbox alone, so a user chat message shows up only here. */
+	hasPendingInput: boolean
 }
 
 /**
@@ -76,7 +78,7 @@ export const batchingDebounceCallback: DebounceCallback = (context) => {
  */
 export const waitForResponseDebounceCallback: DebounceCallback = (context) => {
 	// If we have new messages, process immediately
-	if (context.totalPending > 0) {
+	if (context.totalPending > 0 || context.hasPendingInput) {
 		return 'process_now'
 	}
 
diff --git a/packages/sdk/src/core/tools/context.ts b/packages/sdk/src/core/tools/context.ts
index 6604174c..a069e8b8 100644
--- a/packages/sdk/src/core/tools/context.ts
+++ b/packages/sdk/src/core/tools/context.ts
@@ -1,3 +1,7 @@
 import type { AgentContext } from '../agents/context.js'
+import type { ToolCallId } from './schema.js'
 
-export type ToolContext = AgentContext
+export type ToolContext = AgentContext & {
+	/** The call being executed. `agentState` is captured before it starts, so it cannot tell you this. */
+	toolCallId: ToolCallId
+}
diff --git a/packages/sdk/src/core/tools/executor.test.ts b/packages/sdk/src/core/tools/executor.test.ts
index dcc0ca80..e63ff314 100644
--- a/packages/sdk/src/core/tools/executor.test.ts
+++ b/packages/sdk/src/core/tools/executor.test.ts
@@ -14,6 +14,7 @@ import { SessionFileStore } from '../file-store/file-store.js'
 import type { ToolContext } from './context.js'
 import { createTool } from './definition.js'
 import { ToolExecutor } from './executor.js'
+import { ToolCallId } from './schema.js'
 
 // ============================================================================
 // Test Helpers
@@ -60,6 +61,7 @@ const createTestContext = (): ToolContext => {
 		input: undefined,
 		parentId: null,
 		runAuxiliaryInference: async () => Err({ type: 'invalid_request', message: 'not implemented in test' }),
+		toolCallId: ToolCallId('test-call'),
 	}
 }
 
diff --git a/packages/sdk/src/index.ts b/packages/sdk/src/index.ts
index b1685519..39cb55ac 100644
--- a/packages/sdk/src/index.ts
+++ b/packages/sdk/src/index.ts
@@ -39,6 +39,7 @@ export type { AgentTransportConfig, IAgentTransport, PluginNotification } from '
 // Runtime
 export { Agent } from '~/core/agents/agent.js'
 export type { AgentConfig } from '~/core/agents/agent.js'
+export type { DebounceCallback, DebounceContext, DebounceDecision } from '~/core/agents/debounce.js'
 export { SessionManager } from '~/core/sessions/session-manager.js'
 export type { SessionManagerOptions } from '~/core/sessions/session-manager.js'
 export { SessionRuntimeDetachedError, SessionStore } from '~/core/sessions/session-store.js'