Compare refs

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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds minimal behavioral context (that the result includes a commit list), but does not elaborate on return format, pagination, or how the 'straight' parameter affects the diff.

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, front-loaded with the action and resource, and contains no redundant wording. Every word contributes to understanding the tool's purpose.

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 the 100% schema coverage, read-only annotations, and the description's note that the result includes the commit list, the tool is sufficiently described for a compare operation. The lack of an output schema is partially compensated by mentioning the commit list, though more detail about the response structure would push it to a 5.

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 100%, so all four parameters are already documented in the input schema. The description's mention of 'branches, tags or commits' echoes the schema's 'branch/tag/SHA' but adds no new semantic detail, justifying the baseline score of 3.

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 specifies the action ('Diff') and the resource scope ('between two branches, tags or commits'), and adds that the result includes the commit list. This distinguishes it from sibling tools like gitlab_list_commits or gitlab_get_merge_request_diff by focusing on comparing two arbitrary refs.

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 guidance is provided on when to use this tool versus alternatives, such as gitlab_get_merge_request_diff or gitlab_list_commits. The description only states what the tool does, leaving the agent to infer usage context.

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