EM DC Resistance

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

Annotations already declare readOnlyHint=truecars, and the description adds meaningful behavioral context: the computation is exact, uses a closed-form formula, and optionally includes current and Joule heating when voltage_v is supplied. It also explains how conductivity is sourced. No contradiction with annotations.

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 compact, front-loaded with the core formula and scope, and every sentence adds value: no-solver emphasis, formula, optional voltage behavior, conductivity source, and return shape. There is no wasted text.

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?

For a simple analytic calculator, the description is largely complete: it gives the formula, the source of conductivity, optional voltage behavior, and the return object. Minor gaps remain, such as explicit unit-conversion rules and what happens if neither conductivity_s_m nor conductor is supplied, but these are not severely misleading.

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 0%, so the description must compensate. It explains conductivity_s_m, conductor, and voltage_v semantics, and the return list implies unit conversion from mm to m. However, the required length_mm and area_mm2 are not explicitly described, and precedence between conductivity_s_m and conductor is left ambiguous.

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 precise verb and resource: 'Exact DC resistance of a uniform conductor' and gives the governing formula R = L/(σ·A). It also differentiates from sibling em_conduction_submit by explicitly calling this the 'closed-form anchor' that the solver gate reproduces, so an agent can distinguish it immediately.

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 'NO solver' qualifier and the reference to em_conduction_submit clearly signal this is the analytic, non-solver path for uniform conductors. It implies when to use it versus the numerical solver, though it does not explicitly state exclusions such as 'use em_conduction_submit for non-uniform geometry'.

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