Report API-mutation grants in transcript and improve handling

src/chrome/src/agent/agent.js

@@ -17512,7 +17512,9 @@ Rules: no prose intro, no conclusion, no "this screenshot shows...", no layout d
       return await downloadResourceFromPage(tabId, args);
     }
     if (name === 'download_files' || name === 'download_file') {
-      if (args.url && !args.urls) args.urls = [args.url];
+      if (args.url && (!Array.isArray(args.urls) || args.urls.length === 0)) {
+        args.urls = [args.url];
+      }
       return await downloadFiles(args);
     }
 
@@ -18828,6 +18830,12 @@ Rules: no prose intro, no conclusion, no "this screenshot shows...", no layout d
 
     if (name === 'upload_file') {
       args = args || {};
+      // Some providers materialize omitted optional schema properties as empty
+      // strings. Treat those placeholders as absent so a valid downloadId does
+      // not conflict with a nonexistent user attachment or local path.
+      for (const key of ['selector', 'attachmentId', 'filePath']) {
+        if (typeof args[key] === 'string' && !args[key].trim()) delete args[key];
+      }
       const compactUpload = (
         executionContext?.promptTier || this._resolvePromptTier()
       ) === 'compact';

src/firefox/src/agent/agent.js

@@ -15331,13 +15331,21 @@ Rules: no prose intro, no conclusion, no "this screenshot shows...", no layout d
       return await downloadResourceFromPage(tabId, args);
     }
     if (name === 'download_files') {
-      if (args.url && !args.urls) args.urls = [args.url];
+      if (args.url && (!Array.isArray(args.urls) || args.urls.length === 0)) {
+        args.urls = [args.url];
+      }
       return await downloadFiles(args);
     }
     if (name === 'upload_file') {
       const UPLOAD_MAX_BYTES = 25 * 1024 * 1024;
       try {
         args = args || {};
+        // Some providers materialize omitted optional schema properties as empty
+        // strings. Treat those placeholders as absent so a valid downloadId does
+        // not conflict with a nonexistent user attachment or local path.
+        for (const key of ['selector', 'attachmentId', 'filePath']) {
+          if (typeof args[key] === 'string' && !args[key].trim()) delete args[key];
+        }
         const compactUpload = (
           executionContext?.promptTier || this._resolvePromptTier()
         ) === 'compact';

test/run.js

@@ -54565,6 +54565,72 @@ test('download_files digest echoes safe downloadIds but never the filename (chro
   }
 });
 
+test('download_files falls back to singular url when providers emit an empty urls placeholder', async () => {
+  const originalChrome = globalThis.chrome;
+  const originalBrowser = globalThis.browser;
+  const url = 'https://example.com/webbrain-firefox.zip';
+  try {
+    let chromeDownloadOptions = null;
+    globalThis.chrome = {
+      runtime: { lastError: null },
+      downloads: {
+        download(options, cb) {
+          chromeDownloadOptions = options;
+          cb(468);
+        },
+        search(_query, cb) {
+          cb([{
+            id: 468,
+            filename: '/Users/test/Downloads/webbrain-firefox.zip',
+            state: 'complete',
+            bytesReceived: 10,
+            totalBytes: 10,
+          }]);
+        },
+      },
+    };
+    const chromeArgs = { url, urls: [], filename: 'webbrain-firefox.zip' };
+    const chromeResult = await new AgentCh({}).executeTool(42, 'download_files', chromeArgs);
+    assert.equal(chromeResult.success, true);
+    assert.deepEqual(chromeArgs.urls, [url]);
+    assert.equal(chromeDownloadOptions.url, url);
+
+    let firefoxDownloadOptions = null;
+    globalThis.browser = {
+      storage: {
+        local: {
+          async get() { return { downloadDirectory: '' }; },
+        },
+      },
+      downloads: {
+        async download(options) {
+          firefoxDownloadOptions = options;
+          return 469;
+        },
+        async search() {
+          return [{
+            id: 469,
+            filename: '/Users/test/Downloads/webbrain-firefox.zip',
+            state: 'complete',
+            bytesReceived: 10,
+            totalBytes: 10,
+          }];
+        },
+      },
+    };
+    const firefoxArgs = { url, urls: [], filename: 'webbrain-firefox.zip' };
+    const firefoxResult = await new AgentFx({}).executeTool(42, 'download_files', firefoxArgs);
+    assert.equal(firefoxResult.success, true);
+    assert.deepEqual(firefoxArgs.urls, [url]);
+    assert.equal(firefoxDownloadOptions.url, url);
+  } finally {
+    if (originalChrome === undefined) delete globalThis.chrome;
+    else globalThis.chrome = originalChrome;
+    if (originalBrowser === undefined) delete globalThis.browser;
+    else globalThis.browser = originalBrowser;
+  }
+});
+
 test('download_files treats interrupted browser downloads as failed (chrome & firefox)', async () => {
   const originalChrome = globalThis.chrome;
   const originalBrowser = globalThis.browser;
@@ -55221,7 +55287,9 @@ test('upload_file prefers a valid downloadId and falls back to filePath for an i
     cdpClientCh.getFileInputFiles = async () => [];
     const consumed = await agent.executeTool(42, 'upload_file', {
       selector: 'input[type=file]',
+      attachmentId: '',
       downloadId: 9123,
+      filePath: '',
     });
     assert.equal(consumed.success, true);
     assert.equal(consumed.attachmentState, 'page_consumed');
@@ -55699,7 +55767,12 @@ test('upload_file (firefox) re-fetches downloadId with manual redirect handling
     };
 
     const agent = new AgentFx({});
-    const args = { selector: 'input[type=file]', downloadId: 8123 };
+    const args = {
+      selector: 'input[type=file]',
+      attachmentId: '',
+      downloadId: 8123,
+      filePath: '',
+    };
     const result = await agent.executeTool(42, 'upload_file', args);
 
     assert.equal(result.success, true);