Reply or comment as the channel

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

Annotations already declare this is a non-read-only, non-idempotent, open-world write. The description adds genuinely new behavior: the post is public and attributed to the channel, and a confirmation step is required before posting. It does not cover failure modes, quota cost, or whether the reply is immediately visible.

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?

A single dense sentence with the primary action front-loaded and the mode distinction in parentheses. Every clause carries information, though the nested parentheticals make it slightly harder to scan than a two-sentence split would.

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 public write tool with no output schema, the definition covers the essential mechanics: what gets posted, under whose identity, and the confirmation gate. Missing details are secondary — error behavior, quota impact, and what the response contains after posting.

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 only 40%, so the description must compensate. It does explain comment_id (top-level comment or thread id) and video_id (new top-level comment), but leaves channel and confirmation_token to the schema and says nothing about text constraints (1–10000 chars). Partial compensation warrants a middle 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 names a specific verb and resource ('Post a public reply to a comment' / 'new top-level comment on a video') and disambiguates the two modes by tying each to its parameter (comment_id vs video_id). This clearly separates it from siblings like list_comments, delete_comment, and moderate_comments.

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 two usage modes explicitly and adds the precondition that the user must confirm the exact text first, which tells the agent how to sequence the call. It stops short of naming when to prefer a sibling (e.g., moderate_comments) or what to do if the target comment is gone.

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