list_commits

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

The readOnlyHint annotation already declares the read-only nature, and the description's 'List' aligns with that. It adds minimal context beyond the annotation—only the default-branch behavior, which is also documented in the schema. No additional behavioral details (e.g., sorting, error conditions) are disclosed.

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, front-loaded sentence that immediately identifies the tool's purpose. Every word adds meaning, with no redundancy or filler.

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 simple nature of the tool, the description covers the core behavior and the key default-branch case. Combined with the fully described schema and readOnlyHint annotation, it is largely complete for an agent to select and invoke the tool, though it does not describe the return payload format.

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 adds the notion of 'recent' commits, which is not explicitly stated in the schema, but it adds little beyond the parameter descriptions already present. It does not compensate for any missing parameter semantics because none are missing.

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 uses a specific verb ('List') and resource ('commits') with a clear scope ('on a branch'), and it notes the default branch behavior. This distinguishes it from sibling tools like list_prs and list_branches, which target different resources.

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 the tool is for fetching commit history on a branch, and the default-branch note provides context. However, it does not explicitly state when to prefer this tool over alternatives such as list_prs or list_workflow_runs, nor does it mention exclusions.

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