feat: include page title in list_pages output (#2166)

## Motivation

`list_pages` shows each page's URL but not its title, which is painful
when multiple pages share a host — e.g. several tabs under
`app.example.com/u/0/`, `/u/1/`, `/u/2/`. There's no way to tell which
is which without visiting each one, even though every page has a usable
`document.title`.

Fixes #2156.
Closes #2175

## What this changes

- `list_pages` text output now shows the title before the URL when
available: `1: My Page (https://example.com) [selected]`. If the page
has no title (e.g. `about:blank`), the format is unchanged.
- The structured content entry for each page now includes a `title`
field alongside `id`, `url`, and `selected`.
- `page.title()` is awaited with a `.catch(() => '')` so a closed or
erroring page silently falls back to the URL-only format.
- `format()` is made `async` to support the `await` inside the page
loop; `createStructuredPage()` likewise becomes `async`.

## Testing

Start the MCP server with multiple tabs open. Call `list_pages` — pages
with titles now display as `id: Title (url)`. Pages without titles
(`about:blank`, data URLs) display as before.

---------

Co-authored-by: Piotr Paulski <31672205+zyzyzyryxy@users.noreply.github.com>

src/McpResponse.ts

@@ -759,7 +759,7 @@ export class McpResponse implements Response {
     );
   }
 
-  format(
+  async format(
     toolName: string,
     context: McpContext,
     data: {
@@ -777,7 +777,10 @@ export class McpResponse implements Response {
       errorMessage?: string;
     },
     useToon: boolean,
-  ): {content: Array<TextContent | ImageContent>; structuredContent: object} {
+  ): Promise<{
+    content: Array<TextContent | ImageContent>;
+    structuredContent: object;
+  }> {
     const structuredContent: {
       snapshot?: object;
       snapshotFilePath?: string;
@@ -916,10 +919,14 @@ Call ${handleDialog.name} to handle it before continuing.`);
           const contextLabel = isolatedContextName
             ? ` isolatedContext=${isolatedContextName}`
             : '';
+          const title = await fetchPageTitle(page);
+          const pageLabel = title
+            ? `${truncateTitle(title)} (${page.url()})`
+            : page.url();
           parts.push(
-            `${context.getPageId(page)}: ${page.url()}${context.isPageSelected(page) ? ' [selected]' : ''}${contextLabel}`,
+            `${context.getPageId(page)}: ${pageLabel}${context.isPageSelected(page) ? ' [selected]' : ''}${contextLabel}`,
           );
-          structuredPages.push(createStructuredPage(page, context));
+          structuredPages.push(createStructuredPage(page, context, title));
         }
         response.push(...parts);
         structuredContent.pages = structuredPages;
@@ -934,10 +941,16 @@ Call ${handleDialog.name} to handle it before continuing.`);
             const contextLabel = isolatedContextName
               ? ` isolatedContext=${isolatedContextName}`
               : '';
+            const title = await fetchPageTitle(page);
+            const pageLabel = title
+              ? `${truncateTitle(title)} (${page.url()})`
+              : page.url();
             response.push(
-              `${context.getPageId(page)}: ${page.url()}${context.isPageSelected(page) ? ' [selected]' : ''}${contextLabel}`,
+              `${context.getPageId(page)}: ${pageLabel}${context.isPageSelected(page) ? ' [selected]' : ''}${contextLabel}`,
+            );
+            structuredExtensionPages.push(
+              createStructuredPage(page, context, title),
             );
-            structuredExtensionPages.push(createStructuredPage(page, context));
           }
           structuredContent.extensionPages = structuredExtensionPages;
         }
@@ -1301,16 +1314,37 @@ Call ${handleDialog.name} to handle it before continuing.`);
     this.#textResponseLines = [];
   }
 }
-function createStructuredPage(page: Page, context: McpContext) {
+function truncateTitle(title: string, maxLength = 50): string {
+  if (title.length <= maxLength) {
+    return title;
+  }
+  return title.slice(0, maxLength - 3) + '...';
+}
+
+async function fetchPageTitle(page: Page): Promise<string> {
+  return Promise.race([
+    page.title().catch(() => ''),
+    new Promise<string>(resolve => setTimeout(() => resolve(''), 1000)),
+  ]);
+}
+
+function createStructuredPage(
+  page: Page,
+  context: McpContext,
+  rawTitle: string,
+) {
   const isolatedContextName = context.getIsolatedContextName(page);
+  const title = truncateTitle(rawTitle);
   const entry: {
     id: number | undefined;
     url: string;
+    title: string;
     selected: boolean;
     isolatedContext?: string;
   } = {
     id: context.getPageId(page),
     url: page.url(),
+    title,
     selected: context.isPageSelected(page),
   };
   if (isolatedContextName) {

tests/McpResponse.test.js.snapshot

@@ -324,6 +324,7 @@ exports[`McpResponse > list pages 2`] = `
     {
       "id": 1,
       "url": "about:blank",
+      "title": "",
       "selected": true
     }
   ]
@@ -1286,7 +1287,7 @@ exports[`third-party developer tools > lists third-party developer tools 2`] = `
 
 exports[`webmcp > includes webmcp tools in list_pages response 1`] = `
 ## Pages
-1: about:blank [selected]
+1: My test page (about:blank) [selected]
 ## WebMCP tools
 name="test_tool", description="A test tool", inputSchema={"type":"object","properties":{},"required":[]}, annotations=undefined
 `;
@@ -1297,6 +1298,7 @@ exports[`webmcp > includes webmcp tools in list_pages response 2`] = `
     {
       "id": 1,
       "url": "about:blank",
+      "title": "My test page",
       "selected": true
     }
   ],
@@ -1317,7 +1319,7 @@ exports[`webmcp > includes webmcp tools in list_pages response 2`] = `
 exports[`webmcp > includes webmcp tools in navigate_page response 1`] = `
 Successfully navigated to about:blank.
 ## Pages
-1: about:blank [selected]
+1: My test page (about:blank) [selected]
 ## WebMCP tools
 name="test_tool", description="A test tool", inputSchema={"type":"object","properties":{},"required":[]}, annotations=undefined
 `;
@@ -1329,6 +1331,7 @@ exports[`webmcp > includes webmcp tools in navigate_page response 2`] = `
     {
       "id": 1,
       "url": "about:blank",
+      "title": "My test page",
       "selected": true
     }
   ],
@@ -1348,7 +1351,7 @@ exports[`webmcp > includes webmcp tools in navigate_page response 2`] = `
 
 exports[`webmcp > includes webmcp tools in select_page response 1`] = `
 ## Pages
-1: about:blank [selected]
+1: My test page (about:blank) [selected]
 ## WebMCP tools
 name="test_tool", description="A test tool", inputSchema={"type":"object","properties":{},"required":[]}, annotations=undefined
 `;
@@ -1359,6 +1362,7 @@ exports[`webmcp > includes webmcp tools in select_page response 2`] = `
     {
       "id": 1,
       "url": "about:blank",
+      "title": "My test page",
       "selected": true
     }
   ],
@@ -1379,7 +1383,7 @@ exports[`webmcp > includes webmcp tools in select_page response 2`] = `
 exports[`webmcp > list no webmcp tools if experimentalWebmcp is false 1`] = `
 Successfully navigated to about:blank.
 ## Pages
-1: about:blank [selected]
+1: My test page (about:blank) [selected]
 `;
 
 exports[`webmcp > list no webmcp tools if experimentalWebmcp is false 2`] = `
@@ -1389,6 +1393,7 @@ exports[`webmcp > list no webmcp tools if experimentalWebmcp is false 2`] = `
     {
       "id": 1,
       "url": "about:blank",
+      "title": "My test page",
       "selected": true
     }
   ]

tests/tools/pages.test.js.snapshot

@@ -1,5 +1,5 @@
 exports[`pages > close_page > when dialog is open 1`] = `
-{"content":[{"type":"text","text":"## Pages\\n1: about:blank [selected]"}],"structuredContent":{"pages":[{"id":1,"url":"about:blank","selected":true}]}}
+{"content":[{"type":"text","text":"## Pages\\n1: about:blank [selected]"}],"structuredContent":{"pages":[{"id":1,"url":"about:blank","title":"","selected":true}]}}
 `;
 
 exports[`pages > list_pages > list pages for extension pages with --category-extensions 1`] = `
@@ -25,27 +25,27 @@ exports[`pages > list_pages > list pages for side panels with --category-extensi
 ## Pages
 1: about:blank
 ## Extension Pages
-2: chrome-extension://<extension-id>/sidepanel.html [selected]
+2: Side Panel (chrome-extension://<extension-id>/sidepanel.html) [selected]
 ## Extension Service Workers
 sw-1: chrome-extension://<extension-id>/sw.js
 `;
 
 exports[`pages > list_pages > when dialog is open 1`] = `
-{"content":[{"type":"text","text":"# Open dialog\\nalert: test dialog.\\nCall handle_dialog to handle it before continuing.\\n## Pages\\n1: about:blank [selected]"}],"structuredContent":{"dialog":{"type":"alert","message":"test dialog","defaultValue":""},"pages":[{"id":1,"url":"about:blank","selected":true}]}}
+{"content":[{"type":"text","text":"# Open dialog\\nalert: test dialog.\\nCall handle_dialog to handle it before continuing.\\n## Pages\\n1: about:blank [selected]"}],"structuredContent":{"dialog":{"type":"alert","message":"test dialog","defaultValue":""},"pages":[{"id":1,"url":"about:blank","title":"","selected":true}]}}
 `;
 
 exports[`pages > navigate_page > when dialog is open 1`] = `
-{"content":[{"type":"text","text":"Successfully navigated to data:text/html,<div>Navigated</div>.\\n# Open dialog\\nalert: test dialog.\\nCall handle_dialog to handle it before continuing.\\n## Pages\\n1: data:text/html,<div>Navigated</div> [selected]"}],"structuredContent":{"message":"Successfully navigated to data:text/html,<div>Navigated</div>.","dialog":{"type":"alert","message":"test dialog","defaultValue":""},"pages":[{"id":1,"url":"data:text/html,<div>Navigated</div>","selected":true}]}}
+{"content":[{"type":"text","text":"Successfully navigated to data:text/html,<div>Navigated</div>.\\n# Open dialog\\nalert: test dialog.\\nCall handle_dialog to handle it before continuing.\\n## Pages\\n1: data:text/html,<div>Navigated</div> [selected]"}],"structuredContent":{"message":"Successfully navigated to data:text/html,<div>Navigated</div>.","dialog":{"type":"alert","message":"test dialog","defaultValue":""},"pages":[{"id":1,"url":"data:text/html,<div>Navigated</div>","title":"","selected":true}]}}
 `;
 
 exports[`pages > new_page with isolatedContext > when dialog is open 1`] = `
-{"content":[{"type":"text","text":"# Open dialog\\nalert: test dialog.\\nCall handle_dialog to handle it before continuing.\\n## Pages\\n1: about:blank\\n2: about:blank [selected]"}],"structuredContent":{"dialog":{"type":"alert","message":"test dialog","defaultValue":""},"pages":[{"id":1,"url":"about:blank","selected":false},{"id":2,"url":"about:blank","selected":true}]}}
+{"content":[{"type":"text","text":"# Open dialog\\nalert: test dialog.\\nCall handle_dialog to handle it before continuing.\\n## Pages\\n1: about:blank\\n2: about:blank [selected]"}],"structuredContent":{"dialog":{"type":"alert","message":"test dialog","defaultValue":""},"pages":[{"id":1,"url":"about:blank","title":"","selected":false},{"id":2,"url":"about:blank","title":"","selected":true}]}}
 `;
 
 exports[`pages > resize > when dialog is open 1`] = `
-{"content":[{"type":"text","text":"# Open dialog\\nalert: test dialog.\\nCall handle_dialog to handle it before continuing.\\n## Pages\\n1: about:blank [selected]"}],"structuredContent":{"dialog":{"type":"alert","message":"test dialog","defaultValue":""},"pages":[{"id":1,"url":"about:blank","selected":true}]}}
+{"content":[{"type":"text","text":"# Open dialog\\nalert: test dialog.\\nCall handle_dialog to handle it before continuing.\\n## Pages\\n1: about:blank [selected]"}],"structuredContent":{"dialog":{"type":"alert","message":"test dialog","defaultValue":""},"pages":[{"id":1,"url":"about:blank","title":"","selected":true}]}}
 `;
 
 exports[`pages > select_page > when dialog is open 1`] = `
-{"content":[{"type":"text","text":"# Open dialog\\nalert: test dialog.\\nCall handle_dialog to handle it before continuing.\\n## Pages\\n1: about:blank [selected]"}],"structuredContent":{"dialog":{"type":"alert","message":"test dialog","defaultValue":""},"pages":[{"id":1,"url":"about:blank","selected":true}]}}
+{"content":[{"type":"text","text":"# Open dialog\\nalert: test dialog.\\nCall handle_dialog to handle it before continuing.\\n## Pages\\n1: about:blank [selected]"}],"structuredContent":{"dialog":{"type":"alert","message":"test dialog","defaultValue":""},"pages":[{"id":1,"url":"about:blank","title":"","selected":true}]}}
 `;