Youtube Vision MCP

Instructions

Implementation Reference

• src/index.ts:251-306 (handler)

  Implements the handler logic for the 'ask_about_youtube_video' tool. Parses input arguments using the schema, constructs a prompt (question-specific or general description), calls the shared Gemini API helper with the YouTube video, and handles success/error responses including Zod validation.

  case "ask_about_youtube_video": {
    // Define question variable outside try block to access in catch
    let question: string | undefined;
    try {
      // Parse and validate arguments
      const args = AskAboutYoutubeVideoInputSchema.parse(request.params.arguments);
      const { youtube_url } = args;
      question = args.question; // Assign parsed question here
  
        console.error(`[INFO] Received request for ask_about_youtube_video: ${youtube_url}`);
  
        let finalPrompt: string;
        if (question) {
          // If a question is provided, use the Q&A prompt
          console.error(`[INFO] Question: "${question}"`);
          finalPrompt = `Please answer the following question based on the provided video content:\n\nQuestion: ${question}`;
        } else {
          // If no question, use a general description prompt
          console.error(`[INFO] No question provided, generating general description.`);
          finalPrompt = "Describe this video content in detail.";
        }
  
        // Call Gemini API using the helper function
        const answerOrDescription = await callGeminiApi(finalPrompt, {
          mimeType: "video/youtube",
          fileUri: youtube_url,
        });
  
        console.error(`[INFO] Successfully generated response (answer or description).`);
        // Return success response
        return {
          content: [{ type: "text", text: answerOrDescription }],
        };
  
      } catch (error: any) {
        console.error(`[ERROR] Failed during ask_about_youtube_video tool execution:`, error);
  
        // Handle Zod validation errors
        if (error instanceof z.ZodError) {
          return {
            content: [{ type: "text", text: `Invalid input: ${JSON.stringify(error.errors)}` }],
            isError: true,
          };
        }
  
        // Handle generic errors
        let errorMessage = question ? `Failed to answer the question based on the video.` : `Failed to generate description for the video.`;
        if (error.message) {
          errorMessage += ` Details: ${error.message}`;
        }
        return {
          content: [{ type: "text", text: errorMessage }],
          isError: true,
        };
      }
    }

• src/index.ts:52-56 (schema)

  Zod input schema definition for the 'ask_about_youtube_video' tool, validating youtube_url as a URL and question as optional string.

  const AskAboutYoutubeVideoInputSchema = z.object({
    youtube_url: z.string().url({ message: "Invalid YouTube URL provided." }),
    // Making question optional to handle general description requests as well
    question: z.string().optional().describe("Question about the video content. If omitted, a general description will be generated."),
  });

• src/index.ts:76-80 (registration)

  Registers the 'ask_about_youtube_video' tool in the ListTools response, providing name, description, and converted JSON schema.

  {
    name: "ask_about_youtube_video",
    description: "Answers a question about the video or provides a general description if no question is asked.",
    inputSchema: zodToJsonSchema(AskAboutYoutubeVideoInputSchema), // Schema updated to make question optional
  },