update_pull_request_reviewers

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

With no annotations provided, the description carries the behavioral disclosure burden. It does reveal that this is a write operation, notes provider-dependent support, and describes the return as a "Normalized provider write-result mapping" with an example. However, it does not disclose whether reviewers are replaced or appended, what happens on unsupported providers, or any failure behavior.

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 well-structured with a one-sentence purpose, an Args list, a Returns line, and a concrete example. It is compact and front-loaded, with no filler or repetition of the tool name.

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 presence of an output schema covers return-value expectations, and the example provides a useful concrete call. Still, for a mutation operation with no annotations, the description leaves out important context such as reviewer-set replacement semantics, provider support details, and validation rules, so an agent may not fully understand side effects before invoking it.

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%, so the Args section is the only parameter documentation. It gives one-line meanings for all four parameters, adding terms like "key", "identity", and "usernames or account identifiers", which is helpful but still vague about expected formats and provider-specific values. It compensates minimally for the absent schema descriptions.

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 opens with a specific verb and resource: "Request reviewers" for a pull request, which clearly identifies the operation. It goes beyond a tautology, but it does not explicitly differentiate itself from closely related siblings such as submit_pull_request_review or update_pull_request.

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 "when supported by the provider" hints at a key condition, but the description gives no guidance about when to choose this tool over siblings, what prerequisites are needed, or what circumstances make the operation unsupported. There is no explicit when-to-use or when-not-to-use guidance.

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