Pin comment

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

Annotations already declare non-read-only, idempotent, non-destructive behavior, so the description is not obliged to restate them. It adds real value beyond them by disclosing the ownership error case and the ordering effect ('above all others'), which an agent cannot get from the annotations.

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-loaded with the core action and short overall. The second sentence largely restates the first ('or unpins it' appears twice), which is minor redundancy but not damaging.

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 two-parameter, annotation-covered tool with no output schema, the description is nearly sufficient: it covers ownership constraints and the resulting comment ordering. Only the return behavior and whether only one comment can be pinned at a time are left unspecified.

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% and both parameters (comment_id, unpin) are documented in the schema, so the baseline applies. The description mentions unpinning but adds no syntax, defaults, or format detail beyond what the schema already provides.

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 ('Pin a comment to the top of your post's comments') and names the reciprocal action (unpin). It is clearly distinct from siblings like like_comment or delete_comment, though it never explicitly contrasts with them.

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?

Usage is implied rather than stated: it references 'as Pin in the comment menu does' and notes that comments on someone else's post error out. There is no explicit guidance on when to prefer this over related siblings (like_comment, reply_to_comment) or on prerequisites beyond the ownership constraint.

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