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

Annotations already establish that this is a non-read-only, non-destructive, non-idempotent operation. The description adds meaningful behavioral context by specifying the signing action "discuss" and the reply mechanism through parentId, though it does not cover permissions, rate limits, or full signing details.

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?

The description is three short sentences and front-loads the core action immediately. It is appropriately sized for the tool and contains no obvious filler.

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 an 8-parameter signed mutation with no output schema and 0% schema description coverage, the description is incomplete. It gives useful signing and reply hints but does not explain how to populate kind, timestamp, nonce, publicKey, or signature.

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 description coverage is 0% for 8 parameters, so the description must carry the burden. It explains documentId, body, and parentId semantics, but leaves kind, publicKey, timestamp, nonce, and signature unexplained; it also repeats the body maxLength already present in the schema.

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 a specific verb and resource: "Post a comment on a document." It is clear what the tool does, but it does not explicitly distinguish it from nearby siblings such as suggest_edit or submit_contribution.

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 explains the reply mode by saying to also sign parentId, which is useful usage guidance. However, it does not say when to use this tool versus alternatives like suggest_edit or submit_contribution, nor does it state exclusions.

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