test(mcp): restore omitted-optional lock and name unknown-tool

Author: TheGreatAxios

tests/integration/mcp-late-dispatch.test.ts

@@ -136,7 +136,7 @@ describe("integration — late MCP dispatch", () => {
   );
 
   test.serial(
-    "unadvertised MCP tool dispatch fails loudly instead of altering results",
+    "unknown MCP tool dispatch fails loudly instead of altering results",
     async () => {
       const session = await openIntegrationSession({
         permissionGate: permissionGate(),
@@ -288,6 +288,69 @@ describe("integration — late MCP dispatch", () => {
     },
   );
 
+  test.serial(
+    "tool_search promotion does not inject omitted optional MCP arguments",
+    async () => {
+      const session = await openIntegrationSession({
+        permissionGate: permissionGate(),
+        createAgentFn: createAgentWithLiveToolDispatch,
+      });
+      let receivedArgs: Record<string, unknown> | undefined;
+
+      try {
+        const tools = lateMcpTools((toolName, args) => {
+          if (toolName === "list_issues") {
+            receivedArgs = args;
+          }
+        });
+        expect(tools).toHaveLength(1);
+        expect(tools[0]?.kind).toBe("full");
+        const expectedSchema = structuredClone(LATE_MCP_SCHEMA);
+        session.toolset.dynamicRunner.addTools(tools);
+        session.toolset.setToolPromoter(() => {
+          session.updateToolDefinitions(
+            session.toolset.dynamicRunner.currentDefinitions(),
+          );
+        });
+        session.harness.scenario.replyOnce("anthropic", {
+          toolCalls: [
+            { name: "tool_search", args: { query: "linear list issues" } },
+          ],
+        });
+        session.harness.scenario.replyOnce("anthropic", {
+          toolCalls: [{ name: LATE_MCP, args: { limit: 1 } }],
+        });
+        session.harness.scenario.replyOnce("anthropic", { text: "listed" });
+
+        const { events } = await runUntilDone(session, "list one linear issue");
+        const bodies = await Promise.all(
+          session.harness.scenario
+            .matchedRequests()
+            .map(
+              async (request) =>
+                JSON.parse(
+                  await (request.clone() as unknown as Request).text(),
+                ) as AnthropicRequestBody,
+            ),
+        );
+        const publishedTool = bodies
+          .flatMap((body) => body.tools ?? [])
+          .find((tool) => tool.name === LATE_MCP);
+
+        expect(publishedTool?.input_schema.properties).toEqual(
+          expectedSchema.properties,
+        );
+        expect(
+          Object.hasOwn(publishedTool?.input_schema ?? {}, "required"),
+        ).toBe(false);
+        expect(receivedArgs).toEqual({ limit: 1 });
+        expect(toolDoneContents(events)).toContain("ISSUE-1");
+      } finally {
+        await closeIntegrationSession(session);
+      }
+    },
+  );
+
   test.serial(
     "tool_search promotion preserves required and optional MCP arguments",
     async () => {