run_drc

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

No annotations are provided, so the description carries the full behavioral burden. It does disclose real side effects — it may save the board and refill zones (in the editor too) — and explains a failure mode (stale fills producing false clearance errors). It does not say whether DRC rules must be configured, how long it runs, or what the caller should do with the report, leaving notable gaps for a zero-annotation mutation-adjacent 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?

Front-loaded with the core action before the Args block, and every line earns its place — the refill note even justifies itself with the false-clearance failure mode. Slightly verbose in the parenthetical on refill/save interaction but not wasteful.

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?

For a 3-parameter tool with an output schema (so return values need not be described) and no required parameters, the definition covers all parameters and the main side effects. The missing piece is any pointer to prerequisite tooling such as get_design_rules or the ERC counterpart.

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 0% — the schema only supplies titles and defaults — so the description must compensate, and it does: it explains output_path (optional .json report path, temp file when empty), save_first, and refill_zones with rationale. Meaning is added beyond the bare property names, though it never states that the two booleans default to true.

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?

States a specific verb+resource+scope: 'Run Design Rule Check on the open PCB and summarise the results'. An agent can tell it performs DRC rather than ERC, but the description never names the closest sibling (run_erc) or check_clearance, so differentiation is left to inference rather than made explicit.

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?

Usage is implied by 'on the open PCB', and the parameter notes give conditional guidance (refill when fills are stale after routing, save before checking). However, there is no explicit when-to-use-vs-alternative statement against run_erc or check_clearance, and no prerequisites such as design rules being loaded.

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