bb_get_pr_diffstat

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

The annotations already declare readOnlyHint=true, so the safe read-only nature is covered. The description adds useful behavioral context beyond annotations by specifying exactly what the tool returns: per-file added/removed line counts plus a totals summary. There is no contradiction with annotations, and no hidden side effects are suggested.

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 core purpose and immediately specifies the output scope. There is no filler, repetition, or unnecessary detail.

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 simple read-only tool with full schema coverage, an output schema, and clear annotations, the description is complete. It tells the agent what the tool returns and the schema covers all parameter details. Nothing essential is missing for correct invocation.

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 the schema already documents pr_id, repo_slug, and workspace, including the default behavior for repo_slug. The description adds no additional parameter-level semantics, which is acceptable because the schema carries the full burden. A baseline 3 is appropriate.

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 uses a specific verb ('Get') and a specific resource ('diffstat for a pull request'), and further clarifies what a diffstat is: every modified file with added/removed line counts and a totals summary. This distinguishes it clearly from sibling tools like bb_get_pr_file_diff or bb_get_pr_all_file_diffs, which return file content or diffs rather than aggregate counts.

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 this tool—when you need summary counts rather than actual diffs—but it never explicitly names alternatives or states when not to use it. With siblings like bb_get_pr_file_diff and bb_get_pr_all_file_diffs present, explicit routing guidance would have made the usage intent unambiguous.

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