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

No annotations are provided, so the description carries the full burden. It usefully discloses the method (2D electric-field solver), that copper thickness is accounted for, and that results come with an applicability range, which is genuine behavioral context; but it omits accuracy caveats, unit conventions, or failure conditions.

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 tight sentences front-loaded with the method and the computed quantities, followed by a short note on the return. No filler; each clause 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?

With no output schema, the description helpfully notes that the return carries an applicability range, and the well-documented schema covers geometry and mode selection. For a pure computation tool this is nearly complete, lacking only accuracy/assumption caveats.

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 nine parameters including their roles for ms/sl and diff/single. The description adds nothing parameter-specific beyond what the schema provides, making the baseline 3 appropriate.

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 (numerically solving) and resource (differential/single-ended impedance of microstrip or stripline), plus the exact outputs Zdiff/Zcomm/odd-even/Z0. It clearly distinguishes itself in substance from siblings like crosstalk and diff_skew, though it does not name those siblings explicitly to route the agent.

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: compute impedance for a chosen line kind (kind) and mode (mode), which the description enumerates. However, there is no explicit guidance on when to reach for this tool versus siblings such as crosstalk or diff_skew, nor any prerequisites or exclusion conditions.

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