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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds useful cost information ('1 credit') and the exact computation performed, but never says how resistivity is resolved from the 'material' string (internal lookup table? case sensitivity?) nor the units of the returned resistance.

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: the operation and governing formula come first, followed by a short cost tag. Nothing is redundant and the most decision-relevant information is front-loaded.

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?

There is no output schema, so the description ideally should state that the result is a resistance value in ohms; since R is defined in the formula this is mostly inferable. For a simple three-parameter deterministic calculator, the definition is nearly complete, with only output units and material handling left implicit.

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 each parameter is already fully documented. The description restates ρ, L and A and shows their relationship in the formula, which reinforces but does not materially extend the schema's meaning; the 3 baseline applies.

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 ('Calculates') and an unambiguous resource ('electrical resistance of a wire'), backed by the exact formula R = ρL/A. It does not explicitly differentiate itself from the many sibling calculators (e.g., calculate_electric_field, potential_energy), but the formula makes its scope unmistakable.

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 statement of when to use this tool, when not to, or which sibling to prefer for related electrical/geometry calculations. The formula implicitly scopes it to uniform-wire DC resistance, but no explicit guidance, prerequisites, or alternatives are given.

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