git_diff_stat

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

The annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds that output is compact per file and that base compares revisions, but it also redundantly repeats '(read-only)' and does not add much beyond the annotations.

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 short and front-loaded, with the core purpose in the first clause. '(read-only)' is minor redundancy against the annotations, and the second sentence is terse but useful for the base parameter.

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?

With an output schema and strong read-only annotations, return values and safety need less explanation. However, with 0% schema description coverage and three parameters, the description is not complete enough: it explains only 'base' and omits 'repo' and 'staged', while also failing to distinguish this tool from similar git_diff siblings.

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 0%, so the description must explain all three parameters. It only clarifies 'base' as comparing with a revision and says nothing about 'repo' or 'staged', leaving two parameters undocumented in both schema and description.

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: 'Summarise changes per file', and adds scope with 'compact for large diffs'. It does not explicitly distinguish this from very similar siblings such as git_diff_summary or git_diff, so sibling differentiation is missing.

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 phrase 'compact for large diffs' implies a useful situation, but there is no explicit guidance on when to choose this over git_diff, git_diff_summary, or git_status. The 'base compares with a revision' note gives partial context for one parameter but not broader usage rules.

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