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

With no annotations, the description carries the full burden and does add notable behavioral context: the operation costs $0.005, returns live data as JSON, and requires payment via x402 or a Bearer credits key. This goes well beyond a bare description, though it does not mention rate limits, pagination, or read-only status.

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 very short and every fragment carries distinct information: cost, resource, output type, and auth method. It is front-loaded with the most important operational detail (cost) and has no filler, though the fragmented style slightly hurts readability.

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?

The description does not explain what the response looks like beyond 'JSON', does not define what 'id' refers to (presumably video ID), and gives no indication of how cursor-based pagination works. Since there is no output schema, the description should compensate, but it leaves key usage details ambiguous.

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 documentation coverage is 100%, so the schema fully describes the parameters (id, sort, cursor). The description adds no extra meaning about how these parameters should be used or what values to provide, so the baseline of 3 is appropriate.

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 identifies the resource as 'Video comments — YouTube' and the tool name reinforces it. It is clear that this tool deals with YouTube video comments, but it lacks an explicit verb like 'list' or 'retrieve', so it does not fully meet the highest standard.

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 given about when to use this tool versus siblings such as youtube_video or youtube_search_video. There are no conditions, exclusions, or alternative recommendations, leaving the agent to infer usage from the name alone.

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