route_set_net_class_rules

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

The annotations declare destructiveHint=true, and the description's 'Write' action aligns with that without contradiction. The description adds the context that it targets the 'active .kicad_dru file', which is useful. However, it does not disclose whether this overwrites the entire file, only the specified net class section, or whether existing rules are merged or replaced, leaving important behavioral details unclear for a destructive operation.

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 a single, concise sentence that front-loads the action and target. Every word provides meaning, and there is no redundant fluff. It is appropriately sized for the tool's apparent simplicity, though it could be slightly more informative without becoming verbose.

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's destructive nature, five required parameters, and no parameter descriptions, the description is notably incomplete. It identifies the target file but does not explain the write semantics (overwrite vs. merge), prerequisites, or the impact on existing design rules. The sibling context includes many routing and design-rule tools, but with only this description an agent lacks enough context to safely invoke it.

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?

Parameter schema coverage is 0% and the description provides no parameter information whatsoever. The description does not mention the five required parameters (net_class, width_mm, clearance_mm, via_diameter_mm, via_drill_mm) or explain how they map to routing constraints, units, or validation rules. This is a complete failure to compensate for the lack of schema descriptions.

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 states a specific verb and resource: 'Write net-class routing constraints into the active .kicad_dru file.' This clearly identifies the action and target file. However, it does not explicitly distinguish this from the sibling 'pcb_set_net_class', which could be confused as setting net-class properties rather than writing routing constraint rules.

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?

No guidance is provided on when to use this tool versus alternatives such as 'pcb_set_design_rules' or 'pcb_set_net_class'. There is no mention of prerequisites (e.g., needing an active project or design rule file) or when writing directly to the .kicad_dru file is appropriate versus using other rule-setting tools.

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