analyze_impedance_tolerance

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered by structured data. The description adds that the tool computes cumulative worst-case Zmin/Zmax, sensitivity derivatives and yield, which is meaningful behavior beyond the annotations, but it says nothing about precision limits, model assumptions, or failure cases.

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?

A single dense sentence that front-loads the purpose and standards before the tolerance and return-value detail. Every clause carries information, though the length makes it slightly heavy for one sentence.

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?

With no output schema, describing the produced quantities (Zmin, Zmax, dZ/dW, dZ/dH, yield) is exactly the burden the description must carry, and it does so along with the governing models and the variation assumptions. An agent can invoke this correctly without opening other artifacts.

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%, so the baseline is 3, but the description adds real information the schema does not: copper thickness is varied at a fixed +-15% and Er at a fixed +-5%, neither of which exists as a settable parameter, while width and height tolerances map to width_tolerance_pct and height_tolerance_pct. That tells the agent which knobs are adjustable versus hard-coded.

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 and resource ('Analyze PCB characteristic impedance manufacturing tolerance window and sensitivities') and names the governing standards (IPC-2141A, Polar SI9000), which clearly separates it from nominal-impedance siblings like calculate_trace_impedance or calculate_pcb_stackup_impedance. It stops short of naming those siblings explicitly, so the differentiation is inferred rather than stated.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as calculate_trace_impedance or calculate_differential_skew. The only usage signal is the implied context that this is a tolerance/variation study, which an agent must infer from the wording.

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