Diff two tags or commits to reveal version labels, closures, and differing paths. Read-only.
Compare two tags or commits: their version labels, closures and the paths that differ. Read-only.
| Name | Required | Description | Default |
|---|---|---|---|
| a | Yes | ||
| b | Yes | ||
| repo | Yes | path to a local git repository |
Changes observed during successful MCP inspections.
v1.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the burden; it does declare 'Read-only,' which substitutes for readOnlyHint and is the key safety fact. It also names the categories of output (labels, closures, differing paths). It stops short of describing error behavior for unknown refs or whether the diff is symmetric.
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?
One dense sentence plus a two-word safety tag. The operation and its outputs are front-loaded with zero filler; every clause carries 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?
For a 3-parameter read-only tool with no output schema, the description adequately conveys inputs and output categories but omits directionality of a vs b, behavior on invalid refs, and any pagination or size limits on the differing-paths list.
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 coverage is 33%: only 'repo' is documented in the schema. The description compensates by explaining that a and b are 'two tags or commits', which is the essential semantics of those two params. It does not clarify ordering/direction of the comparison, which matters for interpreting 'paths that differ'.
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?
States a specific verb (compare) and the resources it operates on (two tags or commits), plus what is produced: version labels, closures, and differing paths. It is clear on its own, though it never contrasts itself with siblings like check_versions or explain_label.
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?
No explicit when-to-use guidance, prerequisites, or named alternatives. The phrase 'two tags or commits' implies the input context, but an agent must infer when compare is preferable to check_versions or explain_label.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.