calc_impedance

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

No annotations are provided, so the description carries the burden. It discloses the dual-mode behavior (forward calculation vs reverse calculation) and supported transmission line types, but does not mention edge cases like parameter validation, error handling, or what happens when both width and targetImpedance are provided.

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, compact sentence that front-loads the primary purpose and lists supported modes. Every word earns its place with no redundancy.

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?

The tool has 7 parameters with 100% schema coverage and no output schema. The description covers the core functionality and mode selection, but given the complexity of impedance calculations (multiple modes, mutual exclusivity of width/targetImpedance, differential spacing requirements), it could benefit from noting that spacing is required for differential modes and clarifying the reverse-calculation behavior.

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 the schema already documents all parameters. The description adds the key semantic that width and targetImpedance are mutually exclusive (二选一), which is valuable. However, it doesn't explain the relationship between parameters beyond that, and the schema already covers defaults and units.

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's dual purpose: calculate PCB trace impedance or reverse-calculate trace width from target impedance. It explicitly lists supported modes (microstrip/stripline/differential), which distinguishes it from sibling tools like calc_trace_width.

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 usage context (PCB impedance calculation) but does not explicitly state when to use this tool versus calc_trace_width, which appears to be a closely related sibling. No exclusions or alternative tool references are provided.

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