Get pull request diffstat

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

No annotations are provided, so the description carries the full burden. It indicates a read-only operation with 'Fetches' and describes the output, but it does not disclose potential behavioral traits such as authentication requirements, error cases, or how the diffstat is aggregated (e.g., across the entire PR vs. a specific commit). The description is accurate but minimal.

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 a single, well-structured sentence that front-loads the main action ('Fetches') and concisely states the deliverable. Every word earns its place, with no 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 the tool's low complexity (3 parameters, 1 required, no output schema), the description adequately covers the essential purpose and return value, specifying that it provides added/removed/modified and line counts per file. It lacks details on the exact response structure or possible errors, but for a simple read-only diffstat tool, it is sufficiently complete.

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% with descriptions for all three parameters, including fallback behavior for repoSlug and workspace. The description text adds no further parameter information beyond what the schema provides, so it meets the baseline for high schema coverage without enhancing it.

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 the tool's function: fetching a per-file summary of changes (added/removed/modified, line counts) for a pull request. It uses a specific verb ('Fetches') and resource ('per-file summary'), and the term 'diffstat' naturally distinguishes it from sibling tools like bb_get_pull_request_diff, which returns the actual diff.

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 when to use the tool by specifying 'per-file summary of changes', which suggests it is for summarized views rather than full diffs. However, it does not explicitly name alternatives or provide when-not-to-use guidance, so the usage context is only implied, not clearly stated.

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