get_test_coverage

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

While annotations declare readOnlyHint=true, the description adds crucial behavioral context: it details the return format (per-module summary with file-level test presence and high-complexity function gaps) and discloses tier limitations (Pharaoh Pro vs. free preview constraints). This warns the agent that free tier users receive limited data requiring summarization and upgrade links.

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?

Well-structured with clear sections: purpose statement, usage guidelines (bulleted), return value description, and tier limitations. The tier section is slightly verbose but contains necessary business logic. Information is front-loaded with the core purpose appearing immediately.

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?

Despite lacking an output schema, the description compensates by detailing what the tool returns (per-module summaries, file coverage status, high-complexity function gaps). It also addresses subscription tier constraints, providing sufficient context for a zero-parameter read-only analysis tool.

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 input schema contains zero parameters, which establishes a baseline score of 4. The description appropriately makes no mention of parameters since none exist, requiring no additional semantic clarification beyond the empty schema.

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 'See[s] which modules and files have test coverage and which don't' and specifies it returns a 'Per-module test coverage summary.' This specifically targets test coverage analysis, distinguishing it from sibling tools like get_codebase_map or get_module_context which handle general code structure rather than test-specific gaps.

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?

Contains an explicit 'CALL THIS WHEN:' section with three distinct scenarios: before writing tests, during code review, and when planning test strategy. These concrete use cases provide clear guidance on when this tool is appropriate versus other analysis tools in the suite.

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