graph TD A[Start] --> B[Receive MP4 URL] B --> C[Validate URL Input] C --> D{URL Valid?} D -->|No| E[Return Error] E --> A D -->|Yes| F[Execute Skill #207] F --> G[Process Video URL] G --> H[Generate Transcription] H --> I[Add Timestamps] I --> J[Format Output] J --> K[time-stamped-transcript] K --> L[End]