@@ -11,6 +11,7 @@ import {
   ProviderDriverKind,
   ProviderInstanceId,
   RunId,
+  RuntimeRequestId,
   ThreadId,
   TurnItemId,
   type OrchestrationV2ProjectedTurnItem,
@@ -125,6 +126,85 @@ it.effect("checks capability through the production registration", () =>
   ),
 );
 
+it.effect("an answered question reports already answered instead of not found", () => {
+  const shell = McpToolAccessTestkit.liveThreadShell(threadId);
+  const requestId = RuntimeRequestId.make("answered-question");
+  const projection = McpToolAccessTestkit.idleThreadProjection(shell);
+  return Effect.gen(function* () {
+    const server = yield* McpServer.McpServer;
+    const respond = (id: string) =>
+      server
+        .callTool({
+          name: "t3_pending_request_respond",
+          arguments: { requestId: id, answers: { size: "large" } },
+        })
+        .pipe(
+          Effect.provideService(McpInvocationContext.McpInvocationContext, scope),
+          Effect.provideService(McpSchema.McpServerClient, client),
+        );
+    expect(declaredFailure(yield* respond(requestId))).toMatchObject({
+      code: "invalid_request",
+      message: "The user-input request was already answered.",
+    });
+    expect(declaredFailure(yield* respond("missing-question"))).toMatchObject({
+      code: "invalid_request",
+      message: "The pending user-input request was not found.",
+    });
+  }).pipe(
+    Effect.provide(
+      layerThreadToolkit.pipe(
+        Layer.provideMerge(McpServer.McpServer.layer),
+        Layer.provide(NodeCrypto.layer),
+        Layer.provide(
+          Layer.mock(ThreadManagement.ThreadManagementService)({
+            getThreadShell: () => Effect.succeed(shell),
+            getProjectThreadRecords: () =>
+              Effect.succeed({
+                ...projection,
+                runtimeRequests: [
+                  {
+                    id: requestId,
+                    nodeId: NodeId.make("root"),
+                    providerTurnId: null,
+                    nativeRequestRef: null,
+                    kind: "user_input",
+                    status: "resolved",
+                    responseCapability: { type: "message" },
+                    createdAt: shell.createdAt,
+                    resolvedAt: shell.updatedAt,
+                    answers: { size: "large" },
+                  },
+                ],
+                turnItems: [
+                  {
+                    id: TurnItemId.make("answered-question-item"),
+                    threadId,
+                    runId: null,
+                    nodeId: null,
+                    providerThreadId: null,
+                    providerTurnId: null,
+                    nativeItemRef: null,
+                    parentItemId: null,
+                    ordinal: 0,
+                    status: "completed",
+                    title: null,
+                    startedAt: shell.createdAt,
+                    completedAt: shell.updatedAt,
+                    updatedAt: shell.updatedAt,
+                    type: "user_input_request",
+                    requestId,
+                    questions: [],
+                  },
+                ],
+              }),
+            dispatch: () => Effect.die("an answered question must not dispatch again"),
+          }),
+        ),
+      ),
+    ),
+  );
+});
+
 it("bounds public command rejections and redacts internal dispatch causes", () => {
   const command = { commandId: CommandId.make("mcp-core-command"), commandType: "thread.settle" };
   expect(
 
@@ -55,10 +55,7 @@ const readQuestion = Effect.fn("mcp.readQuestion")(function* (input: {
 }) {
   const context = yield* readThread(input.threadId, ["runtimeRequests", "turnItems"]);
   const request = context.projection.runtimeRequests.find(
-    (request) =>
-      request.id === input.requestId &&
-      request.kind === "user_input" &&
-      request.status === "pending",
+    (request) => request.id === input.requestId && request.kind === "user_input",
   );
   const item = context.projection.turnItems.find(
     (item) => item.type === "user_input_request" && item.requestId === input.requestId,
@@ -68,6 +65,14 @@ const readQuestion = Effect.fn("mcp.readQuestion")(function* (input: {
       code: "invalid_request",
       message: "The pending user-input request was not found.",
     });
+  if (request.status !== "pending")
+    return yield* new OrchestratorMcpFailure({
+      code: "invalid_request",
+      message:
+        request.status === "resolved"
+          ? "The user-input request was already answered."
+          : `The user-input request is no longer pending (${request.status}).`,
+    });
   return { ...context, request, item };
 });
 const writesThread = <P extends { readonly threadId?: ThreadId | undefined }, A, E, R>(