update_pull_request

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

The description discloses a genuinely important behavioral trait—preserving reviewers and approval status when reviewers are not specified—which is valuable beyond the basic update action. However, with no annotations, it does not address permissions, reversibility, or other side effects, so it is only partially transparent.

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 just two sentences, front-loaded with the primary action and immediately followed by a critical caveat. There is no filler or redundancy.

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?

Given 7 parameters, no annotations, and no output schema, the description covers the key reviewer preservation nuance but omits other update semantics (e.g., partial vs full update, response shape, prerequisites). The schema fills parameter details, but the tool description is lean for a mutation tool.

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?

All seven parameters are already fully described in the input schema (100% coverage), and the tool description essentially repeats the reviewer caveat already present in the schema. It adds no new semantic value beyond what the schema 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 uses a specific verb and resource ('Update an existing pull request') and adds a clarifying behavioral note about reviewer preservation, which helps distinguish it from create_pull_request or merge_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 'existing pull request' clearly signals it is for modifying already-created PRs, and the reviewer caveat gives a concrete usage condition. It does not explicitly mention alternatives like create_pull_request, but the context and sibling tool names make the use case clear.

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