update_pr

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

Annotations already indicate this is a mutating, non-destructive, idempotent operation. The description adds valuable behavioral context by disclosing the PATCH-like semantics: only supplied fields change, and omitted fields keep their current values. It does not detail side effects such as closing a PR via the state field, but that information is present in the schema.

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 two sentences with no filler. It front-loads the core action and then immediately gives the most important behavioral nuance, followed by a concrete example. Every sentence 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?

Given the output schema exists and the annotations cover safety and idempotency, the description is mostly complete for effective invocation. It lacks guidance on sibling specializations, which could matter in this large toolset, but the essential call semantics are clear.

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 schema already provides useful descriptions for base, body, state, and title. The description adds the critical partial-update interpretation, clarifying that parameters are optional and that omitting them is not a reset. This meaningfully compensates for the partial schema description coverage and helps an agent call the tool correctly.

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 verb and resource: 'Updates an existing pull request.' It is clear and unambiguous. However, it does not distinguish this general tool from sibling update tools like update_pr_branch, update_pr_description, or update_assignees.

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 implies the tool is appropriate for partial updates by explaining that only supplied fields are sent and other fields retain their values. It does not explicitly state when to prefer this tool over specialized siblings, nor does it give exclusions like 'use update_pr_branch for base retargeting.'

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