Evaluate Rego with coverage

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

Annotations already indicate readOnly=true, destructive=false, idempotent=true. The description adds that it returns per-line coverage data, which is useful behavioral detail. No contradictions. It could mention that evaluation is side-effect-free, but annotations cover that.

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 sentences: first states the action and output, second gives usage context. No redundant words, front-loaded with key information. Highly concise.

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?

With 8 parameters and no output schema, the description is brief. It does not explain the output format (e.g., structure of coverage data), error handling, or performance implications. While the schema covers parameters, additional context about return values would improve completeness.

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 baseline is 3. The description does not elaborate on parameters beyond what the schema already provides (e.g., mutual exclusivity of source/paths, input/inputPath). No added value for parameter semantics.

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 evaluates with --coverage and returns per-line coverage data. This distinguishes it from siblings like rego_eval, rego_eval_with_explain, rego_eval_with_profile, and rego_coverage_gaps by specifying the exact feature (coverage).

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?

The description says 'Useful for verifying that tests actually exercise the rules they're meant to,' which gives clear context for when to use it (for test coverage). However, it lacks explicit guidance on when not to use it or how it compares to alternatives like rego_test or rego_coverage_gaps.

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