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

Annotations declare readOnlyHint=true, so the safety profile is covered. The description adds behavioral context by explaining what includeDiff and includeRebasePreview return (conflicts, classified changes, behind count) and the prerequisite of project context. This goes beyond the annotations without contradicting them.

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, front-loaded with the primary purpose, and each sentence earns its place. It efficiently describes the optional flags and the prerequisite without extraneous detail. The structure is clear and scannable.

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 read-only tool with 4 parameters and no output schema, the description covers the return values (counts, optional diff, rebase preview) and a prerequisite. It does not describe error handling or explicit return format, but the counts and flag behavior give an agent enough to call it correctly. The absence of an output schema means the description carries more weight, but it is largely sufficient.

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 the baseline is 3. The description enhances the parameter semantics by explaining the purpose of includeDiff ('the read to trust before merging') and includeRebasePreview ('see how far the branch is behind main'), which adds usage meaning beyond the terse schema descriptions. It doesn't elaborate on specId/branchId, but those are self-explanatory GUIDs.

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 gets a single branch and reports counts of endpoints, schemas, and folders. It also specifies optional flags for diff and rebase preview, making the purpose unambiguous. While it doesn't explicitly differentiate from list_branches, the word 'one' and the resource name make the distinction clear.

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 context for when to use the optional flags ('before merging' for includeDiff, 'how far the branch is behind main' for includeRebasePreview) and mentions a prerequisite ('Requires project context'). However, it does not explicitly compare with sibling tools like list_branches or get_merge_request, so guidance on when to choose this tool over alternatives is implied rather than stated.

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