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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation profile is known. The description adds genuine context beyond that: the target draft is dropped, nothing is published externally, and a non-pending target yields a 409 not_pending error — useful nuance for a destructive operation.

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?

Four short sentences, front-loaded with the action and its effect, then the constraint, then the request shape. No filler, nothing to cut.

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 one-parameter mutation with no output schema, the description covers effect, precondition, error signal, and body format, and annotations cover safety. The only gap is not distinguishing this from the bulk and approve variants.

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% for the single required id, so the schema carries parameter meaning. The description adds request-shape guidance ("Send an empty JSON object as the body"), which is helpful, but it never clarifies that id is the comment-reply identifier rather than something else.

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?

Clear verb+resource ("Reject a reply") plus a concrete effect statement ("Drops the pending draft. Nothing is posted."). It doesn't name its obvious siblings approve_comment_reply or bulk_reject_comment_replies, so an agent must infer single-item vs bulk and approve vs reject from the name alone.

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?

Explicit precondition: "Only a pending comment can be rejected (409 not_pending)" tells the agent when the call is legal and what failure looks like. It stops short of naming approve_comment_reply as the alternative action, so the when-to-use-vs-sibling dimension is implied rather than stated.

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