diff --git a/src/agents/generated-attachments.ts b/src/agents/generated-attachments.ts
index 4eb11c08ff7..01fef25efec 100644
--- a/src/agents/generated-attachments.ts
+++ b/src/agents/generated-attachments.ts
@@ -73,7 +73,7 @@ export function formatGeneratedAttachmentLines(
     if (path) {
       parts.push(`path=${JSON.stringify(path)}`);
     } else if (url) {
-      parts.push(`url=${JSON.stringify(url)}`);
+      parts.push(`mediaUrl=${JSON.stringify(url)}`);
     }
     lines.push(parts.join(" "));
   }
diff --git a/src/agents/tools/video-generate-tool.test.ts b/src/agents/tools/video-generate-tool.test.ts
index a8666154761..9f9239bcdb4 100644
--- a/src/agents/tools/video-generate-tool.test.ts
+++ b/src/agents/tools/video-generate-tool.test.ts
@@ -501,7 +501,7 @@ describe("createVideoGenerateTool", () => {
 
     expect(saveSpy).not.toHaveBeenCalled();
     expect(text).toContain("Generated 1 video with vydra/veo3.");
-    expect(text).toContain('url="https://example.com/generated-lobster.mp4"');
+    expect(text).toContain('mediaUrl="https://example.com/generated-lobster.mp4"');
     expect(text).not.toContain("MEDIA:");
     const details = resultDetails(result);
     expect(details.provider).toBe("vydra");
@@ -552,7 +552,7 @@ describe("createVideoGenerateTool", () => {
     const text = (result.content?.[0] as { text: string } | undefined)?.text ?? "";
 
     expect(text).toContain("Generated 1 video with fal/fal-ai/minimax/video-01-live.");
-    expect(text).toContain('url="https://fal.run/files/generated-lobster.mp4"');
+    expect(text).toContain('mediaUrl="https://fal.run/files/generated-lobster.mp4"');
     expect(text).not.toContain("MEDIA:");
     const details = resultDetails(result);
     expect(details.provider).toBe("fal");
@@ -658,7 +658,7 @@ describe("createVideoGenerateTool", () => {
         name: "lobster.mp4",
       },
     ]);
-    expect(wake.result).toContain('url="https://example.com/generated-lobster.mp4"');
+    expect(wake.result).toContain('mediaUrl="https://example.com/generated-lobster.mp4"');
     expect(wake.result).not.toContain("MEDIA:");
   });