testTraceToSource

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

Description adds context beyond readOnlyHint annotation by specifying file dependencies and fallback behavior. No contradictions with annotations.

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 efficient sentences that capture core functionality, file formats, and fallback behavior without extraneous information.

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?

Covers input and fallback but lacks output format details and error handling, which would be helpful given no 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?

Input schema has 100% description coverage; the tool description adds no further semantic detail beyond the schema parameters.

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?

Clearly states it maps test pattern to covered source lines using lcov.info or coverage-summary.json, with a fallback to whole-suite coverage. Distinguishes from siblings like getCodeCoverage by specifying file formats and no instrumentation.

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?

Implies usage for tracing test patterns to source lines but does not explicitly state when to use over alternatives like getCodeCoverage, nor provides exclusions or prerequisites.

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