Codex-YMT has 13 well-named tools with consistent verb_noun patterns (youtube_*). All tools have descriptions (avg ~80 chars, within baseline 34-392). Input schemas are present and typed for all tools. However, parameter descriptions are sparse or missing context; many lack guidance on valid ranges, formats, or dependencies. Output schemas are not documented. Error handling exists but lacks recovery guidance. No tool annotations (readOnlyHint/destructiveHint) despite clear risk classifications in metadata.

• Document output schemas for all tools. E.g., youtube_get_channel should specify: {channel_id: string, title: string, description: string, subscriber_count: integer, ...}. Include which fields are needed for downstream tool calls (e.g., video_id for youtube_get_video).
• Add format/range constraints to parameter descriptions. E.g., 'max_results: integer, 1-50 (default 20)' and 'language: ISO 639-1 language code (e.g., es, fr, de)'. Replace free-form descriptions with enums where applicable.
• Implement tool annotations in the MCP schema. Mark youtube_auth_disconnect, youtube_localize_video_publish, youtube_delete_draft with destructiveHint=true. Mark read-only tools with readOnlyHint=true. This enables agent safety checks.
• Enhance error messages with recovery guidance. E.g., 'Video not found. Call youtube_list_videos() to see available videos.' or 'OAuth expired. Call youtube_auth_start() to reconnect.'
• Document pagination fully. youtube_list_videos should return {videos: [...], total_count: integer, next_page_token: string|null} so LLMs know when to stop iterating.