YouTube 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 the action ('Get comments') but doesn't disclose key traits like whether this is a read-only operation, potential rate limits, authentication needs, error handling, or what the output looks like (though an output schema exists). For a tool with no annotations, this is a significant gap in transparency, as it leaves the agent guessing about operational constraints.

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 appropriately sized and front-loaded, starting with the core purpose followed by parameter details. It uses two sentences efficiently, with no wasted words. The structure is logical, but it could be slightly improved by integrating usage context or behavioral notes, keeping it concise while adding value.

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 tool's moderate complexity (2 parameters, no annotations, but with an output schema), the description is minimally adequate. It covers the purpose and parameters but lacks behavioral transparency and usage guidelines. The presence of an output schema means the description doesn't need to explain return values, but it should still address when to use the tool and operational aspects. This results in a baseline completeness with clear gaps.

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?

The description adds meaningful context beyond the input schema, which has 0% description coverage. It explains that 'video_url' is a 'YouTube video URL' and 'limit' is the 'Maximum number of comments' with default and max values. This compensates well for the low schema coverage, providing clear semantics for both parameters. However, it doesn't detail format specifics (e.g., URL structure), so it doesn't achieve a perfect score.

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 tool's purpose: 'Get comments from a YouTube video.' It specifies the verb ('Get') and resource ('comments from a YouTube video'), making it easy to understand. However, it doesn't explicitly differentiate from sibling tools like 'get_video_info' or 'get_transcript', which could also involve video-related data retrieval, so it doesn't reach a score of 5.

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?

The description provides no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools like 'get_video_info' (which might include comments) or 'search_transcript' (which could involve comment-like text). There's no context on prerequisites, such as needing a valid video URL, beyond what's implied in the parameters. This lack of explicit usage instructions limits its effectiveness for an AI agent.

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