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

Annotations only declare the safety profile (non-read-only, non-destructive, non-idempotent); the description adds real behavioral context beyond them: the permission floor ('Any team role'), a hard length limit, an explicit error case (nested replies rejected), and the notification side effect of mentions. It also closes with the return shape ('Returns the new comment').

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?

Front-loads the core action, then the reply constraint, permission, limit, and mention syntax in a tight sequence with no filler. The mention guidance duplicates the body property description word-for-word, which is redundancy rather than added value.

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?

No output schema exists, and the description compensates by stating what is returned. Together with permissions, size limit, nesting rules, and mention mechanics, an agent has everything needed to call this correctly on the first attempt.

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 100%, so the baseline is 3, but the description adds meaning the schema lacks: parentCommentId carries the one-level nesting constraint and the correct fallback (reply to the top-level comment instead). The mention token format is restated almost verbatim from the body property, so there is little net-new parameter information beyond the reply rule.

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?

States a specific verb and resource (post a comment) plus the two supported targets (task or project) and the reply variant. An agent can distinguish it from edit_comment, delete_comment, and list_comments without opening any schema.

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?

Gives concrete preconditions: any team role is permitted, nesting is capped at one level ('a reply to a reply is rejected'), and a 10,000-character limit applies. It also routes the agent to list_users to resolve mention ids. It stops short of naming sibling alternatives (e.g., edit_comment vs. posting a new one) explicitly.

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