diff_commits

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

With no annotations provided, the description carries the full burden of behavioral transparency. It discloses that output 'can produce very large output' and describes the return type as 'detailed file changes with diff hunks'. While it doesn't explicitly state read-only behavior, the 'Get' verb and diff context make it implicit, and the size warning is valuable.

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 three sentences: the primary action, the return type, and a size warning with an alternative. It is front-loaded and contains no filler. Every sentence delivers useful information.

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 no output schema, the description adequately explains the return value ('detailed file changes with diff hunks') and flags large output. It also names the alternative tool. It does not cover potential error conditions or prerequisites (e.g., valid commit hashes), but these are largely implied by the schema and the nature of the tool, so the description is reasonably 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?

The schema provides 100% coverage for parameters, each with a clear description (e.g., 'Source commit hash'). The tool description does not add extra meaning beyond the schema; it simply refers to 'two commits' which aligns with the parameter names. Baseline 3 applies as the schema already documents parameters adequately.

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 opens with 'Get a full line-by-line diff between two commits', which is a specific verb+resource that clearly identifies the tool's function. It also distinguishes itself from siblings by explicitly mentioning get_commit_files as a lighter alternative for changed-file summaries.

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 explicitly provides guidance: 'Use get_commit_files for a lightweight summary of changed files instead.' This tells the agent when to choose the alternative and implies this tool is for cases requiring a full detailed diff.

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