fix(tabs): say a reply will WAKE you with a new message (clearer than 'arrives on its own')

Matches actual behavior: a peer's reply wakes this tab with a new message in a
later turn. Updated the send_to_tab description (both canReadTab branches), the
delivery-result text (both branches), and the system-prompt one-liner; updated
the test assertion accordingly.

3 files changed, 8 insertions, 8 deletions

diff --git a/packages/api/src/agent-manager.ts b/packages/api/src/agent-manager.ts
index 3d233fc..684f8ec 100644
--- a/packages/api/src/agent-manager.ts
+++ b/packages/api/src/agent-manager.ts
@@ -84,7 +84,7 @@ const TOOL_DESCRIPTIONS: Record<string, string> = {
 	youtube_transcribe:
 		"Fetch the transcript/subtitles for a YouTube video. Set background=true to start in the background and get a job_id for later retrieval.",
 	send_to_tab:
-		"Send a message to another tab (agent) by its short ID, as shown in the tab bar. Fire-and-forget: it queues/wakes the target and returns immediately without waiting for a reply. Do NOT sleep, poll, or run commands to wait — a reply arrives on its own in a later turn; if you are only waiting, end your turn.",
+		"Send a message to another tab (agent) by its short ID, as shown in the tab bar. Fire-and-forget: it queues/wakes the target and returns immediately without waiting for a reply. Do NOT sleep, poll, or run commands to wait — if the target replies it will wake you with a new message in a later turn; if you are only waiting, end your turn.",
 	read_tab:
 		"Read another tab (agent)'s most recent completed response by its short ID. Returns a non-blocking snapshot; if the target is still running you get its previous completed turn. Use after send_to_tab to collect a reply.",
 };
diff --git a/packages/core/src/tools/send-to-tab.ts b/packages/core/src/tools/send-to-tab.ts
index 50023a7..eae6bfa 100644
--- a/packages/core/src/tools/send-to-tab.ts
+++ b/packages/core/src/tools/send-to-tab.ts
@@ -63,11 +63,11 @@ function renderOpenHandles(handles: Array<{ handle: string; title: string }>): s
 export function createSendToTabTool(callbacks: SendToTabCallbacks): ToolDefinition {
 	// The `read_tab` follow-up hint is only truthful when this tab actually
 	// holds the `read_tab` tool (the permissions are split). When it doesn't,
-	// the only honest guidance is that a reply arrives on its own — never tell
+	// the only honest guidance is that a reply will wake it as a new message — never tell
 	// the agent to call a tool it wasn't granted.
 	const waitLine = callbacks.canReadTab
-		? "money. If the target replies it arrives on its own as a new message in a later turn; you"
-		: "money. If the target replies it arrives on its own as a new message in a later turn.";
+		? "money. If the target replies it will WAKE you with a new message in a later turn; you"
+		: "money. If the target replies it will WAKE you with a new message in a later turn.";
 	const readTabLine = callbacks.canReadTab
 		? ["can also call 'read_tab' with the same ID in a FUTURE turn to check. If you have other"]
 		: [];
@@ -176,13 +176,13 @@ export function createSendToTabTool(callbacks: SendToTabCallbacks): ToolDefiniti
 				const tail = callbacks.canReadTab
 					? [
 							"Do NOT sleep, poll, or run commands to wait for a reply. If the target replies it",
-							`arrives on its own as a new message later; you can also call read_tab with "${target.handle}"`,
+							`will WAKE you with a new message later; you can also call read_tab with "${target.handle}"`,
 							"in a FUTURE turn to check. Keep working if you have other tasks; if you are ONLY",
 							"waiting for this reply, end your turn now.",
 						]
 					: [
 							"Do NOT sleep, poll, or run commands to wait for a reply. If the target replies it",
-							"arrives on its own as a new message later. Keep working if you have other tasks; if",
+							"will WAKE you with a new message later. Keep working if you have other tasks; if",
 							"you are ONLY waiting for this reply, end your turn now.",
 						];
 				return [
diff --git a/packages/core/tests/tools/send-to-tab.test.ts b/packages/core/tests/tools/send-to-tab.test.ts
index 48ff460..21d8032 100644
--- a/packages/core/tests/tools/send-to-tab.test.ts
+++ b/packages/core/tests/tools/send-to-tab.test.ts
@@ -38,8 +38,8 @@ describe("createSendToTabTool — schema & description", () => {
 	it("never mentions read_tab in the description when canReadTab is false", () => {
 		const tool = createSendToTabTool(makeCallbacks({ canReadTab: false }));
 		expect(tool.description).not.toContain("read_tab");
-		// Still tells the agent a reply arrives on its own + to end its turn.
-		expect(tool.description.toLowerCase()).toContain("arrives on its own");
+		// Still tells the agent a reply will wake it + to end its turn.
+		expect(tool.description.toLowerCase()).toContain("wake you with a new message");
 		expect(tool.description.toLowerCase()).toContain("end your turn");
 	});
 });