1 files changed, 14 insertions, 2 deletions

diff --git a/packages/core/tests/tools/send-to-tab.test.ts b/packages/core/tests/tools/send-to-tab.test.ts
index 4450fc5..68f8fa0 100644
--- a/packages/core/tests/tools/send-to-tab.test.ts
+++ b/packages/core/tests/tools/send-to-tab.test.ts
@@ -24,6 +24,9 @@ describe("createSendToTabTool — schema & description", () => {
 		expect(tool.name).toBe("send_to_tab");
 		expect(tool.description).toContain("fire-and-forget");
 		expect(tool.description.toLowerCase()).toContain("queued");
+		// Description must steer the model away from busy-waiting for a reply.
+		expect(tool.description.toLowerCase()).toContain("do not sleep");
+		expect(tool.description.toLowerCase()).toContain("end your turn");
 	});
 });
 
@@ -35,11 +38,20 @@ describe("createSendToTabTool — execute()", () => {
 		expect(deliver).toHaveBeenCalledTimes(1);
 		const [targetId, delivered] = deliver.mock.calls[0] ?? [];
 		expect(targetId).toBe("target-id");
-		// Provenance prefix names the sending tab's handle.
-		expect(delivered).toContain("[message from tab self]");
+		// Provenance header names the sending tab's handle and marks it as a
+		// peer agent (not the recipient's own user).
+		expect(delivered).toContain("[message from tab self");
+		expect(delivered).toContain("another agent");
 		expect(delivered).toContain("hello there");
+		// Reply contract: the recipient must answer via send_to_tab back to the
+		// sender's handle, not as a plain text reply to its own user.
+		expect(delivered).toContain('send_to_tab tool with tab_id "self"');
+		expect(delivered.toLowerCase()).toContain("only reply if");
 		expect(out).toContain("idle");
 		expect(out).toContain("targ");
+		// Sender is steered away from busy-waiting and told to end its turn.
+		expect(out.toLowerCase()).toContain("do not sleep");
+		expect(out.toLowerCase()).toContain("end your turn");
 	});
 
 	it("reports the queued status when the target is busy", async () => {