diff --git a/clients/web/src/components/screens/AppsScreen/AppsScreen.test.tsx b/clients/web/src/components/screens/AppsScreen/AppsScreen.test.tsx
index 1525d508..78502392 100644
--- a/clients/web/src/components/screens/AppsScreen/AppsScreen.test.tsx
+++ b/clients/web/src/components/screens/AppsScreen/AppsScreen.test.tsx
@@ -10,6 +10,7 @@ import {
   screen,
   within,
 } from "../../../test/renderWithMantine";
+import { setAceTextByLabel } from "../../../test/aceEditor";
 import {
   AppsScreen,
   type AppsScreenProps,
@@ -320,6 +321,35 @@ describe("AppsScreen", () => {
     expect(screen.getByTitle("Weather Widget")).toBeInTheDocument();
   });
 
+  // The Apps counterpart of the same wire claim (#2171): an App's arguments are
+  // a `tools/call` like any other, so a refused draft must not open the app.
+  it("dispatches nothing for a draft the schema would retype", async () => {
+    const user = userEvent.setup();
+    const onOpenApp = vi.fn();
+    const numericApp: Tool = {
+      name: "chart",
+      title: "Chart Widget",
+      inputSchema: {
+        type: "object",
+        properties: { count: { type: "number" } },
+      },
+      _meta: { ui: { resourceUri: "ui://apps/chart" } },
+    };
+    renderWithMantine(
+      <ControlledAppsScreen tools={[numericApp]} onOpenApp={onOpenApp} />,
+    );
+    await user.click(screen.getByText("Chart Widget"));
+    await user.click(screen.getByLabelText("Edit as JSON"));
+    await setAceTextByLabel(/Arguments JSON/, '{"count":"01"}');
+    await user.click(screen.getByRole("button", { name: /Open App/ }));
+
+    expect(onOpenApp).not.toHaveBeenCalled();
+
+    await setAceTextByLabel(/Arguments JSON/, '{"count":1}');
+    await user.click(screen.getByRole("button", { name: /Open App/ }));
+    expect(onOpenApp).toHaveBeenCalledWith("chart", { count: 1 });
+  });
+
   it("seeds schema defaults so untouched fields are sent on Open App", async () => {
     const user = userEvent.setup();
     const onOpenApp = vi.fn();
diff --git a/clients/web/src/components/screens/ToolsScreen/ToolsScreen.test.tsx b/clients/web/src/components/screens/ToolsScreen/ToolsScreen.test.tsx
index 225b80fc..608e84c9 100644
--- a/clients/web/src/components/screens/ToolsScreen/ToolsScreen.test.tsx
+++ b/clients/web/src/components/screens/ToolsScreen/ToolsScreen.test.tsx
@@ -3,6 +3,7 @@ import { describe, it, expect, vi } from "vitest";
 import userEvent from "@testing-library/user-event";
 import type { Tool } from "@modelcontextprotocol/client";
 import { renderWithMantine, screen } from "../../../test/renderWithMantine";
+import { setAceTextByLabel } from "../../../test/aceEditor";
 import { noopPagination } from "../../../test/fixtures/pagination";
 import {
   ToolsScreen,
@@ -157,6 +158,43 @@ describe("ToolsScreen", () => {
     );
   });
 
+  // #2171's acceptance asks for a test that pins the WIRE rather than the form
+  // state. Under the refusal answer the wire claim is that nothing is sent, and
+  // `onCallTool` is where a dispatch would begin — so a screen that flagged the
+  // draft but still fired the callback would satisfy every other test here.
+  //
+  // The plain and "Run as task" paths need no separate case: the split between
+  // `callTool` and `callToolStream` happens in `App.tsx`, downstream of this
+  // callback, so a gate that stops the callback stops both.
+  it("dispatches nothing for a draft the schema would retype", async () => {
+    const user = userEvent.setup();
+    const onCallTool = vi.fn();
+    const numeric: Tool[] = [
+      {
+        name: "add",
+        inputSchema: {
+          type: "object",
+          properties: { count: { type: "number" } },
+        },
+      },
+    ];
+    renderWithMantine(
+      <ControlledToolsScreen tools={numeric} onCallTool={onCallTool} />,
+    );
+    await user.click(screen.getByText("add"));
+    await user.click(screen.getByLabelText("Edit as JSON"));
+    await setAceTextByLabel(/Arguments JSON/, '{"count":"01"}');
+    await user.click(screen.getByRole("button", { name: /Execute/ }));
+
+    expect(onCallTool).not.toHaveBeenCalled();
+
+    // And it is the draft that blocks it, not the screen: rewritten with the
+    // declared type, the very same click dispatches.
+    await setAceTextByLabel(/Arguments JSON/, '{"count":1}');
+    await user.click(screen.getByRole("button", { name: /Execute/ }));
+    expect(onCallTool).toHaveBeenCalledWith("add", { count: 1 }, false);
+  });
+
   it("filters the sidebar list as the search text changes", async () => {
     const user = userEvent.setup();
     renderWithMantine(<ControlledToolsScreen />);