Server provides 7 tools with explicit schemas and descriptions. Tool naming follows verb_noun conventions consistently (get_*, search_*). Descriptions are present and moderately detailed (80-200 chars), meeting baseline minimums. However, several critical gaps emerge: (1) output schemas are NOT documented anywhere, the code shows ListToolsRequestSchema returns tool definitions but actual response structures are invisible; (2) parameter descriptions lack implementation details (e.g., what happens on invalid language code? What format does 'segment' use?); (3) error handling is not evident in the visible code, no recovery guidance, no error categorization; (4) the server uses an external library (headless-youtube-captions) with @ts-ignore, obscuring actual return types; (5) no pagination guidance despite tools like get_channel_videos accepting maxVideos (suggests potential unbounded results). Tool composition is sound, each tool has a single responsibility, and naming is clear. Parameter constraints are present (enums for sortBy, limits for maxResults). However, the absence of documented output schemas and error recovery patterns significantly limits agent planning capability.

• Document output schemas for all 7 tools. For each, define: (a) response object structure (e.g., { transcript: string, segmentCount: number, language: string }), (b) per-field types and descriptions, (c) example responses. Use a JSON Schema or code comment block visible in the ListToolsRequestSchema response.
• Add explicit error handling with categorization. For each tool, document: (a) common error conditions (e.g., 'Video not found', 'Invalid language code', 'Rate limit exceeded'), (b) whether the error is retryable, (c) recovery guidance (e.g., 'Try search_youtube_global() to find the correct video ID'). Return structured errors: { error: string, code: 'NOT_FOUND'|'INVALID_PARAM'|'RATE_LIMIT', retryable: boolean, suggestion?: string }.
• Enhance get_youtube_transcript description: state what happens if lang is unavailable, document segment discovery (e.g., 'Call with segment=1 to get the first ~98k characters; if the response has total_segments > 1, iterate with segment=2, 3, etc.'), and clarify whether partial matches (en-US) are supported.
• Add pagination metadata to list tools. get_channel_videos and search_channel_videos should return: { videos: [...], total_count: number, has_next: boolean, next_cursor?: string }. Document in tool descriptions.
• Replace @ts-ignore with proper type definitions or update the external library import. Ensure headless-youtube-captions types are available, or wrap calls with typed error boundaries that expose error conditions to tool handlers.
• Add tool-annotation hints to the ListToolsRequestSchema response. Include readOnlyHint: true for all 7 tools so agents know they are safe to retry without side effects.