fix: handle inherited property names in MCP server listings

src/tools/ToolSearch.ts

@@ -897,7 +897,7 @@ function getDeferredToolsListing(
     return '';
   }
 
-  const toolsByServer: Record<string, string[]> = {};
+  const toolsByServer: Record<string, string[]> = Object.create(null);
 
   for (const lcTool of toolRegistry.values()) {
     if (onlyDeferred && lcTool.defer_loading !== true) {
@@ -971,7 +971,7 @@ function formatServerListing(
   const toolsByServer: Record<
     string,
     Array<{ name: string; description: string }>
-  > = {};
+  > = Object.create(null);
   for (const tool of tools) {
     const server = extractMcpServerName(tool.name) ?? 'unknown';
     if (!(server in toolsByServer)) {

src/tools/__tests__/ToolSearch.server-key.test.ts

@@ -0,0 +1,88 @@
+import { describe, expect, it } from '@jest/globals';
+import type { LCToolRegistry, ToolMetadata } from '@/types';
+import {
+  createToolSearch,
+  formatServerListing,
+  getDeferredToolsListing,
+} from '../ToolSearch';
+
+function registry(server: string): LCToolRegistry {
+  return new Map([
+    [
+      'weather_mcp_weather',
+      {
+        name: 'weather_mcp_weather',
+        description: 'Read the weather forecast',
+        defer_loading: true,
+      },
+    ],
+    [
+      `status_mcp_${server}`,
+      {
+        name: `status_mcp_${server}`,
+        description: 'Read service status',
+        defer_loading: true,
+      },
+    ],
+  ]);
+}
+
+function metadata(server: string): ToolMetadata[] {
+  return Array.from(registry(server).values(), (tool) => ({
+    name: tool.name,
+    description: tool.description ?? '',
+  }));
+}
+
+async function expectWeatherSearch(server: string): Promise<void> {
+  const search = createToolSearch({
+    mode: 'local',
+    toolRegistry: registry(server),
+  });
+  const result = await search.invoke({
+    query: 'weather',
+    mcp_server: 'weather',
+  });
+  expect(JSON.parse(result)).toMatchObject({
+    found: 1,
+    tools: [{ name: 'weather_mcp_weather', score: 1 }],
+  });
+}
+
+describe('MCP server grouping accepts ordinary string identifiers', () => {
+  it('keeps an ordinary two-server listing', () => {
+    const listing = getDeferredToolsListing(registry('status'), true);
+    expect(listing).toContain('weather: weather');
+    expect(listing).toContain('status: status');
+  });
+
+  it('searches the healthy server in the ordinary control', async () => {
+    await expectWeatherSearch('status');
+  });
+
+  describe.each(['constructor', 'toString', 'hasOwnProperty'])(
+    'server %s',
+    (server) => {
+      it('can build the initial deferred-tool listing', () => {
+        const listing = getDeferredToolsListing(registry(server), true);
+        expect(listing).toContain(`${server}: status`);
+        expect(listing).toContain('weather: weather');
+      });
+
+      it('can format a server preview', () => {
+        const result = formatServerListing(metadata(server), [server, 'weather']);
+        expect(JSON.parse(result)).toMatchObject({
+          total_tools: 2,
+          tools_by_server: {
+            [server]: [{ name: `status_mcp_${server}` }],
+            weather: [{ name: 'weather_mcp_weather' }],
+          },
+        });
+      });
+
+      it('does not prevent ranked search for another server', async () => {
+        await expectWeatherSearch(server);
+      });
+    }
+  );
+});