update_pr_comment

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

Annotations already provide mutation and idempotency hints, but the description adds important non-obvious behavior: conversation and review comments have separate id spaces and the kind must match the source of the id. This goes beyond the structured annotations and helps prevent a real failure mode.

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?

Two sentences with no filler. The core action is front-loaded, and the critical id-space caveat follows immediately. Every word earns its place.

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?

The description covers the key mutation and the id-space/kind constraint, and an output schema exists so return values need not be described. However, it lacks explicit guidance for choosing between sibling comment tools and does not explicitly map 'review comments' to the 'inline' enum value, which a less experienced agent could misinterpret.

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 low (only comment_id is documented), so the description carries significant weight. It explains the relationship between kind and comment_id, which is the most ambiguous part of the schema. repo_owner, repo_name, and body are not elaborated, but their names are largely self-explanatory.

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 clearly states the action ('Rewrites a comment already posted') with a specific verb and resource. It distinguishes this from adding or replying to comments through the 'already posted' qualifier, though it does not explicitly name sibling tools or contrast 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?

The phrase 'already posted' implies this tool is for existing comments rather than new ones, and the kind/comment-id guidance is useful when invoking. However, it never explicitly says when to use this tool versus add_pr_comments, add_inline_pr_comment, or reply_to_review_comment, so alternative selection is left to inference.

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