yt_list_comments

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

Beyond the readOnly/idempotent annotations, it discloses quota cost (~1 unit), the single-page/no-pagination behavior with a hard cap of 100, the fields returned, and a concrete failure mode (comments disabled). These are exactly the operational traits annotations cannot express.

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?

Three dense sentences, front-loaded with purpose then narrowed to the API cost, return shape, page cap, cross-tool linkage, and failure condition. No filler or redundant restatement of the title.

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?

There is no output schema, so the description compensates by listing the returned fields and the reply count. Combined with the quota, pagination limit, error condition, and the hand-off to yt_reply_comment, an agent has everything needed to call it correctly.

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 only 33% schema description coverage, the description must carry the load: it partially does by stating the 100-item cap (relevant to limit) and framing results as top-level threads. However, the order parameter (time vs relevance) is never explained in the description or the schema, and limit's default relationship to the page cap is left implicit.

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 names a specific verb+resource ('Read top-level comment threads on a video'), gives the underlying API method (commentThreads.list), and enumerates exactly what is returned (commentId, author, text, likes, publishedAt, replyCount, first replies). It is clearly distinct from sibling write tools like yt_post_comment and yt_reply_comment.

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?

It states the follow-on routing explicitly ('Use a returned commentId as yt_reply_comment's parent_id') and discloses a pre-condition for use ('Fails if comments are disabled'), plus the 'Single page, max 100' constraint that tells an agent not to expect pagination. It stops short of naming an alternative for fetching more than one page or for reading replies beyond the first few.

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