github_issues_create_comment

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

Annotations supply readOnlyHint=false and openWorldHint=true, so write/non-deterministic behavior is already declared. The description adds the non-obvious behavioral nuance that PR numbers are accepted in the same field as issue numbers, but says nothing about auth requirements, rate limits, or failure behavior. With annotations carrying the safety profile, this is adequate but not rich.

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 short sentences, zero filler, with the core action front-loaded and the PR-number caveat immediately after. Every clause 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?

For a simple four-parameter write tool with no output schema, the definition covers the action, the resource, and the one genuinely surprising detail (PR numbers reuse the issue number field). Annotations cover the write/open-world profile, so the remaining omission (auth/error behavior) is minor.

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 100% and all four parameters are documented, so the baseline is 3. The description's note about pull request numbers largely restates what the schema already says under issueNumber, adding little parameter meaning beyond the structured fields.

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 (post a comment) and resource (issue or pull request), and immediately resolves the ambiguity that a pull request number is used in the same field. An agent can distinguish this from sibling write tools like slack_chat_post_message or gdocs_documents_create 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?

The description clarifies that both issues and pull requests are valid targets, which is genuinely useful routing information. However, it never states when to use this versus alternatives (e.g., PR review comments) or any precondition such as repo access, leaving usage implied rather than explicit.

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