pcb_drc

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

With no annotations provided, the description carries the full burden. It discloses headless operation, the return structure, and importantly the error behavior ('Fails closed'), which adds critical transparency about failure modes.

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 efficiently cover purpose, output, and error handling with zero waste. Every word earns its place.

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?

While the description covers the core action and return format well, it does not mention prerequisites (e.g., that the board must be loaded or configured) or clarify what 'headless' implies. Given the tool's moderate complexity, a bit more context 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 coverage is 100% with clear parameter descriptions, so baseline is 3. The description does not add extra meaning beyond the schema for parameters; it focuses on output instead.

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 specifies the action ('Run headless Design Rule Check'), the resource ('PCB'), and details the output format (violations grouped by rule with severities, mm coordinates, totals, and JSON report path), clearly distinguishing it from sibling tools like pcb_overview or pcb_net_lengths.

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 implies this tool is for running DRC when you need violation data, but it does not explicitly state when to use it versus alternatives like pcb_render for visuals or pcb_net_lengths for specific checks. Still, the context is clear enough for an agent to infer usage.

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