git_diff

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

Annotations already declare readOnly, idempotent, and non-destructive, covering the safety profile. The description adds the scope of comparison (working tree, index, revisions) but does not disclose output format details, path filtering, or merge-base behavior. No contradiction with annotations is present.

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 concise sentence with no wasted words. It front-loads the verb and clearly conveys the core function, making it easy to read and understand.

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?

The tool has 7 parameters, multiple enums, and an output schema, yet the description is minimal. It lacks explanation of how to specify revisions, use the path filter, choose formats, or interpret results. Even with an output schema, the description is insufficient for a complex tool.

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 only 14% (only repositoryId has a description). The description does not explain base, head, mode, path, format, or mergeBase parameters, forcing the agent to infer from enum names and defaults. This is a significant gap given the low schema coverage.

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 compares working tree, index, or two revisions, giving a specific verb and resource. This distinguishes it from siblings like git_status (which reports status) and git_compare_refs (which likely focuses on refs), though it doesn't explicitly name alternatives.

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 provides no guidance on when to use this tool versus alternatives like git_status, git_compare_refs, or git_range_diff. No exclusions or conditions are stated, leaving the agent to infer usage from the schema enums alone.

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