update_pull_request

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

With no annotations provided, the description fully carries the burden of behavioral disclosure. It clearly explains PATCH semantics (only provided fields change), label replacement behavior, base retargeting irreversibility, and state reopening. This is comprehensive.

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 concise, using two sentences with parenthetical clarifications and a colon. It is well-structured and front-loads the core purpose. Every sentence adds meaningful information, though it could benefit from slight reorganization.

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 11 parameters, no output schema, and no annotations, the description covers critical behaviors, alternatives, and warnings. However, it omits what the response looks like (e.g., returns the updated PR object) and any permission requirements, which are gaps for completeness.

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 coverage is 100%, so baseline is 3. The description adds value beyond the schema by highlighting risk factors (label replacement, base retargeting) and explaining the interaction between state and merging. However, many parameter descriptions in the schema already convey key semantics, so the added value is moderate.

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 'Update one pull request by index' with PATCH semantics. It distinguishes the tool from siblings like merge_pull_request and create_pull_request by detailing specific fields and behaviors, including the state and label replacement caveats.

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 explicitly advises using add_issue_labels/remove_issue_label for single label changes, leveraging the fact that PRs and issues share label endpoints. It also clarifies when to set state to 'closed' vs 'open'. However, it does not broadly cover when not to use this tool in favor of other siblings (e.g., merge_pull_request).

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