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

Annotations already declare readOnlyHint/idempotent/destructive=false, so the safety profile is covered. The description adds method-level context (demand factor, minimum standard service size) but says nothing about how the results are presented or what the minimum-size output means; the omission tip is also questionable given non-zero schema defaults.

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?

One dense sentence plus a single operational tip, front-loaded with the method name and scope. Slightly list-heavy but nothing is wasted.

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?

An output schema exists so return values need no explanation, and annotations plus 100%-covered parameters leave little else to document. The only real gap is the unresolved tension between the 'omit to get 0 VA' tip and the non-zero defaults.

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 every parameter is already documented with units and defaults. The description's only added guidance ('leave an appliance out to count it as 0 VA') is ambiguous and appears to conflict with schema defaults such as hvac=5000, range=12000, dryer=5000, so it does not reliably add meaning.

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?

Names the specific standard and method (NEC 220.82 optional method) and enumerates exactly what it computes: lighting VA/ft², small-appliance and laundry circuits, fixed appliances, demand factor, HVAC, and minimum service size. This clearly separates it from siblings like nec_ampacity, voltage_drop, or bid_calculator.

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 one practical usage tip ('Leave an appliance out to count it as 0 VA'), but no statement of when to prefer this optional method over the standard method or which sibling to use for related calculations. Usage is implied by the NEC reference rather than stated.

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