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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered and the description is free to add the computational contract — the exact allowance formula and the per-AWG volume table. It does not say what the response looks like (required volume only, or required vs. available with a pass/fail), which is the remaining gap for a tool with no output schema.

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?

Front-loaded with the computation and NEC citation, then the formula, then the constant table — a logical order with no filler. The single long formula sentence and the trailing allowance list are dense but each carries information an agent cannot get from the schema.

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 an 11-parameter tool with no output schema, the definition supplies the formula and constants needed to predict the result, and the all-optional schema is mitigated by the stated defaults in the parameter descriptions. It stops short of specifying the return shape (units, whether a compliance verdict is included) and what happens when box='custom' with box_volume_cuin=0.

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; the description earns above that by mapping each parameter to its role in the formula ('1 allowance for clamps', '+2 per yoke', '+1 for all grounds', 'each at the largest conductor size present') and by listing the per-AWG allowances the count_6…count_14 fields feed into. The box enum and box_volume_cuin interaction (custom box with marked volume) remains unexplained.

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 — computing required electrical box volume under NEC 314.16 — and scopes it to conductors, devices, clamps, fittings and grounds. No sibling in the calc_* family addresses box fill, so it is unambiguously distinguishable from the rest of the list.

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 phrase 'checked against a standard metal box from Table 314.16(A) or your box's marked volume' implies the sizing/compliance use case, but the description never states when to reach for this versus a generic volume or conduit calc, nor any prerequisites (e.g., know your conductor counts). Usage is inferable rather than stated.

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