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

Annotations already mark the tool read-only, idempotent, open-world, and non-destructive, and the description adds important behavior beyond that: results are stored rather than freshly computed, waived rules were never evaluated and are listed separately, and an unrun result is explicitly not a pass. This substantially helps an agent interpret the response correctly.

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 compact, front-loaded with the primary use case, and every sentence adds signal: when to use it, what it returns, how waived rules behave, and the critical caveat that 'not run' is not equivalent to passing. There is no filler or repetition.

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 five-parameter schema with complete descriptions, an output schema, and safety annotations, the description covers all the contextual information an agent needs: when to select the tool, how to interpret results, and how to avoid confusing missing checks with a pass. No important behavioral gaps remain.

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 all five parameters—board, rules, cursor, vendor, and category—are already documented in the schema. The description adds general output context such as paged example violations and per-category counts, but it does not need to compensate for schema gaps, so 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 names a specific operation—returning stored DRC and ERC results for a board's current version—and lists the categories covered (design rules, unconnected copper, parity, ERC). It distinguishes itself from a design review and implies it is not running checks, making its purpose unambiguous.

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?

It gives explicit entry conditions: use when the user asks whether a board passes KiCad's own checks, or before trusting a design. It also sets boundaries, noting it is not a design review and that a 'checks not run' result is not the same as passing, though it does not explicitly name sibling tools like run_checks or review_board as alternatives.

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