Compare repository refs

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds that it returns commits and diffs, but doesn't disclose details like pagination, diff size limits, or whether the comparison is bidirectional. With annotations present, this is adequate but not rich.

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 that front-loads the core purpose and return value. No wasted words.

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 5 parameters, an output schema, and clear annotations. The description covers the core purpose but doesn't explain the optional parameters (unidiff, straight) or any edge cases. Given the output schema exists, return values are covered, but the description could be more complete about parameter semantics and usage context.

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 20% (only 'project' has a description). The description doesn't explain 'from', 'to', 'unidiff', or 'straight' parameters. However, the parameter names are fairly self-explanatory (from/to refs, unidiff format, straight comparison), and the description mentions 'branches, tags, or commits' which hints at the ref types. Baseline 3 is appropriate given the schema's minimal coverage but the description's partial compensation.

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 two refs and returns commits plus per-file diffs. It distinguishes from siblings like list_commits or get_commit by focusing on comparison, 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 implies usage for comparing branches, tags, or commits, but doesn't provide explicit when-to-use vs alternatives or exclusions. It's clear enough for a comparison tool but lacks guidance on when to prefer it over list_commit_diffs or get_merge_request_diffs.

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