brain_coverage

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

No annotations are provided, so the description carries the full burden. It clearly states the tool is read-only (reports a score), provides an example output format, and implies no destructive side effects. This is sufficient behavioral transparency for a non-mutating diagnostic tool.

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 extremely concise (three sentences) and front-loaded with the core purpose. Every sentence adds value: purpose, report contents, usage guidance, alternative tool, example output. No wasted words.

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?

Given the tool has a simple input schema (no nested objects, no output schema), the description is comprehensive enough. It covers purpose, report components, usage timing, alternative tool, and output format. The only minor gap is lack of description for the actual parameters, but the schema already handles those adequately with 100% coverage.

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% (both repo_path and instance_id have descriptions in the schema). The description adds value by explaining the tool's output and usage context, but it does not elaborate on the parameters themselves beyond what the schema already says. Baseline 3 is appropriate.

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 computes a 'knowledge-coverage health score' (0-100) for the codebase, listing specific report components. The verb 'reports' and resource 'knowledge-coverage health score' are specific and distinct from sibling tools like brain_metrics or brain_from_git.

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 advises running 'after brain_from_git or periodically to track knowledge-capture progress,' providing clear usage context. It also mentions using 'skill_gaps to find what to fix,' offering a named alternative for further action. There are no explicit when-not-to-use warnings, but the context is clear enough.

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