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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds the backing REST endpoint (GET .../commits/), which is useful provenance but does not disclose pagination behavior, ordering, or result shape beyond the schema.

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?

Two tightly written sentences with the primary purpose front-loaded and zero filler. The REST endpoint reference is compact and earns its place as provenance.

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 list tool with a fully documented schema and explicit readOnlyHint, the description is complete enough for correct invocation. Lack of return-format detail is acceptable since no output schema exists but the description is not required to fill that gap here.

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 six parameters are already documented in the schema. The description repeats branch filtering but adds no syntax, format, or defaults beyond what the schema provides; baseline 3 applies.

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 ('List') and resource ('a repository's commits') with the scoping qualifier 'optionally filtered by branch'. Clear enough to distinguish from write siblings like codecov_get_commit, though it doesn't explicitly contrast the list/get boundary.

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?

'optionally filtered by branch' implies usage context, but there is no explicit when-to-use, when-not, or named alternative (e.g., codecov_get_commit for a single commit). Usage is left to inference.

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