list_video_comments

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

Annotations already indicate readOnlyHint and openWorldHint. Description adds value by detailing the returned structure (snippet.topLevelComment with fields and replies.comments[]), enhancing transparency beyond annotations.

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?

Two sentences, front-loaded with main action and resources, no unnecessary text. Each sentence adds distinct value: purpose and output details, then usage guidance.

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?

For a tool with no output schema and only annotations, the description covers main operation, filtering, pagination, and return fields. It could note that at least one of video_id or channel_id is typically needed, but schema allows both optional. Still fairly complete.

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?

With 100% schema coverage, the schema already describes all parameters. Description adds meaning by explaining usage of search_terms and page_token, going beyond the schema descriptions.

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?

Description clearly states 'Fetch top-level comment threads for a video or all comments on a channel' with specific verb and resource, and distinguishes between video and channel contexts. It also lists returned fields, providing clear purpose.

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?

Description explains using search_terms for filtering and page_token for pagination, offering practical usage guidance. However, it does not explicitly mention when not to use this tool or alternatives like list_comment_replies.

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