YouTube Transcript MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states what the tool does but doesn't cover critical aspects like whether it requires authentication, rate limits, pagination behavior, error handling, or what format the URLs are returned in (e.g., full URLs, video IDs). This leaves significant gaps for an agent to use it effectively.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, efficient sentence that front-loads the core purpose without unnecessary words. Every part of the sentence earns its place by specifying the action and target, making it easy to parse quickly.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the lack of annotations and output schema, the description is incomplete for effective use. It doesn't explain return values (e.g., list of URLs, error formats), behavioral traits like rate limits, or how it differs from siblings. For a tool with 2 parameters and no structured output info, more context is needed to guide the agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, with clear descriptions for both parameters in the input schema. The description doesn't add any additional meaning beyond the schema, such as examples of valid playlist URLs or clarification on how 'maxVideos' interacts with playlist size. Baseline 3 is appropriate since the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Get video URLs') and target resource ('from a YouTube playlist'), making the purpose immediately understandable. However, it doesn't differentiate from sibling tools like 'youtube_get_playlist_videos' or 'youtube_get_channel_video_urls', which might retrieve similar content but from different sources or in different formats.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is provided on when to use this tool versus alternatives. With siblings like 'youtube_get_playlist_videos' and 'youtube_get_playlist_info', the description lacks context on whether this tool is preferred for URLs only, batch processing, or specific use cases, leaving the agent to infer usage from tool names alone.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.