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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so safety is covered. The description adds genuine domain behavior beyond that: device boxes count as '2 each' and the allowance is multiplied by the Table 314.16(B) volume for the largest conductor, which tells the agent how the result is derived.

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 resource and standard, with every clause carrying a computational rule. No filler, though the packing of allowances into one sentence makes it slightly hard to parse.

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 an output schema present, return values need not be explained, and all five parameters are documented in the schema. The description supplies the calculation model, leaving only when-to-use guidance as a gap, which is minor for a deterministic calculator.

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 baseline is 3, but the description adds real semantics: it clarifies that each device contributes 2 conductor volumes and that 'conductors' excludes grounds while the largest conductor drives the multiplier. These are non-obvious details not fully spelled out in the schema.

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 calculation (minimum outlet box volume) with a concrete standard (NEC 314.16(B)) and enumerates the inputs it combines, so an agent can tell it apart from siblings like conduit_fill or load_calculator. It is clear and specific, though it never names a sibling tool to further sharpen the boundary.

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 technical framing (NEC 314.16(B) box fill) implies the usage context, but there is no explicit when-to-use statement, no prerequisites, and no alternative named (e.g., conduit_fill for raceway fill). Usage must be inferred from the domain.

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