Get pull request

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds one useful behavioral detail — that mergeability is computed and returned — but says nothing about what happens for nonexistent PRs or other runtime 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?

A single short sentence with zero padding, front-loading the verb and resource immediately.

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 read-only single-entity fetch with three fully documented required params, the essentials are present. With no output schema, however, the description could say more about the returned payload than just mergeability, leaving the response shape underspecified.

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 100%, so owner, repo and index are all documented in the schema. The description adds no additional meaning (e.g., that index is the PR number, not an internal ID), so the baseline 3 applies.

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?

States a specific verb and resource ('Get a pull request') and adds a scope hint ('including mergeability') that separates it from the list-oriented siblings. It does not name list_pull_requests or other retrieval alternatives, so it stops short of full sibling differentiation.

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 gives no when-to-use conditions, no prerequisites, and does not point to list_pull_requests for enumerating PRs or to get_pull_request_diff for file-level data. Usage is only inferable from the name and the required pull request number.

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