update_pull_request

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=true, which informs the safety profile. The description adds the reversible nature of open/closed state changes, which is useful context. However, it doesn't disclose auth requirements or side effects beyond what annotations already convey. With annotations present, the bar is lower and this adequately complements them.

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?

Two short sentences with zero waste. The first sentence identifies the action and scope, the second adds an explicit exclusion. Every word earns its place and the key information is front-loaded.

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 mutation tool with 7 parameters, no output schema, and very low schema coverage, the description is thin. It covers the what and what-not-to-do, but given the richer parameter surface and no output schema, additional guidance about required fields, state semantics, or expected responses would make it more complete. However, the description plus idempotent annotation covers core usage adequately for a straightforward update operation.

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 very low (14%), with only the 'repository' parameter having a description. The description lists updatable fields (title, body, state) which helps map to parameters, but it doesn't add meaning for account, hostname, or pullRequestNumber. With such low coverage, the description should compensate more, but it only names the fields without providing format, defaults, or relationship guidance.

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?

Description states a specific verb+resource ('Update a pull request') and explicitly lists the updatable fields (title, body, reversible open/closed state). It also distinguishes itself by stating what it cannot do ('This cannot merge a pull request'), which differentiates it from the sibling merge_pull_request tool.

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 clarifies scope by listing the mutable fields and explicitly stating what cannot be done (merging). It provides clear context on what's updateable. However, it doesn't mention when to prefer this over update_issue or comment_pull_request, nor describe prerequisites like required permissions, though the clear operation scope partially compensates.

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