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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds the 'Navy' formula context, which is genuinely useful, but omits the sex-conditional input contract and the units default that affect behavior.

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 tightly written sentence with the verb front-loaded and no filler. It is appropriately short for the tool, though brevity comes at the cost of the missing conditional detail.

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 cover the safety profile. However, with 7 parameters and a sex-conditional oneOf requirement, the description is too thin on the input contract and units handling to be fully complete.

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 71% and the schema documents most parameters, so baseline 3 applies. The description's 'sex and tape measurements' is vague and does not clarify the oneOf conditional (waist/hip required for female, abdomen for male) or the metric/imperial units parameter.

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?

Specific verb+resource: it states it calculates Navy-method body fat percentage and hints at inputs (sex, tape measurements). This distinguishes it from the many other calculators, though it does not explicitly name the closest sibling (bmi_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?

No guidance on when to use this versus bmi_calculator or other body-composition tools, and no mention of the sex-conditional input requirement (abdomen for male, waist/hip for female) or the metric/imperial default. The agent gets no routing or precondition help.

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