List comments

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

The readOnlyHint annotation already covers the safety profile, so the bar is lower. The description adds real value with the 'newest first' ordering, the enumerable moderation states, and the fact that replies are included. It omits pagination behavior despite exposing page_token, and says nothing about quota consumption, which matters for a YouTube-backed API that has a quota_status sibling.

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 dense sentences, scoping and ordering front-loaded, with no filler. Every clause carries information the caller needs.

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?

With no output schema and only read-only annotations, the description should carry more of the load for a seven-parameter list tool with page_token and a max_results cap of 100. Pagination and the relevance ordering option are the notable holes; the coverage of scope, status, and replies is otherwise adequate.

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 coverage is 29%, so the description must compensate, and it partly does by naming the three status values, the search-text filter, and that video_id may be omitted for a channel-wide sweep. It leaves channel, page_token, and max_results unexplained and never mentions that the order parameter also accepts 'relevance', which 'newest first' arguably obscures.

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 states the verb implicitly ('Comment threads on...') and the exact resource, comment threads, plus the two scopes: one video or the whole channel. This separates it cleanly from moderate_comments and delete_comment, which act on comments rather than reading them. It stops short of naming a sibling, so a 4 rather than a 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 gives strong implied usage: read comments, filtered by moderation state or search text, with replies included. It never says when to prefer this over moderate_comments or when to page through results, and gives no prerequisites such as needing a connected channel. Usage is inferable but not spelled out.

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