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

readOnlyHint=true already tells the agent this is a safe read. The description adds value by disclosing that the response includes coverage totals and a report, but omits any auth/token requirements, rate-limit notes, or error behavior for an unreachable commit SHA.

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 short sentences: the purpose is front-loaded and the REST path follows as supporting detail. No filler, though the raw path template adds little for an agent that never calls the HTTP endpoint directly.

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 single-item read with no output schema, the description does sketch the return contents (coverage totals and report), which helps. However, it leaves open the response shape and whether an unknown commit SHA errors versus returns empty, gaps that matter without an output schema.

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 (repo, owner, service, commitid) are already documented in the schema with examples and the service enum. The description contributes nothing beyond restating the endpoint path template, so the 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+resource: retrieving a single commit's detail including coverage totals and report. It implicitly separates from sibling codecov_list_commits (plural) and from codecov_get_coverage_totals, though it never names those siblings explicitly.

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 when-to-use guidance, prerequisites, or alternatives are stated. The word 'single' hints at the distinction from codecov_list_commits, but the agent is left to infer when this tool is preferable to the list or coverage-totals tools.

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