Test Coverage Analysis

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds specific metrics it computes, which is useful context beyond the annotations. However, it does not disclose output format, pagination, or any other behavioral details, and since annotations cover the core traits, a score of 3 is appropriate.

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 that front-loads the purpose ('Test coverage analysis') and follows with specific metrics. There is no wasted verbiage, and it is efficiently structured for quick comprehension.

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?

The tool has no output schema, so the description should explain what the tool returns. It does not mention the output format or contents, leaving a gap. Given the simplicity of the tool (1 param) and available annotations, some return-value information is expected but missing, making it incomplete for an agent to fully understand the tool's behavior.

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?

The single parameter 'path' is fully documented in the schema with 'Absolute path to the repository root', yielding 100% schema description coverage. The description does not add any additional semantics beyond the schema, so the baseline of 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?

The description clearly states the tool performs test coverage analysis and lists specific metrics (test/source ratio, assertion-free tests, skipped tests), which differentiates it from siblings like type_coverage and find_untested. However, it does not explicitly mention what the tool returns or how it differs from other analysis tools beyond these metrics, so it stops short of a 5.

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 given on when to use this tool versus alternatives. The description implies it is for test coverage analysis, but does not state when to prefer this over type_coverage or find_untested. The sibling list includes many related analysis tools, and the description provides no exclusions or selection criteria.

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