Approve pull request at exact head

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

Even with annotations present, the description adds substantial behavioral context: it is additive, caller cannot select credentials, the server verifies multiple preconditions, the write is attempted once, and an immutable review-ID readback verifies APPROVED state, actor, head, and body. It also explicitly rules out fallback comments, merges, dismissals, and ambiguous retries.

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 dense but every sentence adds necessary behavioral or safety information. It is front-loaded with the core action and then systematically covers preconditions, credential handling, verification, and non-behaviors without 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 a write operation with moderate complexity, the description covers purpose, preconditions, side effects, failure semantics, actor constraints, and verification. With an output schema available and rich annotations, no significant contextual gap remains.

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?

The input schema already provides 100% parameter coverage with clear descriptions, so the baseline applies. The description reinforces the meaning of expected_head_sha and expected_reviewer_login, but it does not add significant parameter-specific meaning beyond what the schema already states.

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 action: submit exactly one formal GitHub APPROVED review at a supplied exact pull-request head. It is clearly distinguished from sibling tools by explicitly saying it never comments as a fallback, merges, or dismisses reviews.

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 makes its use case clear by emphasizing approval at an exact head and requiring an expected reviewer login. It also implicitly excludes fallback behaviors such as commenting or merging, but it does not explicitly name alternative tools like gh_request_pr_changes or gh_comment_pr_review.

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