calculate_body_fat_navy

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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It fails to mention any behavior beyond the calculation itself, such as whether it is read-only, any required permissions, or the nature of the output. This is a significant gap for a tool with six parameters.

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?

The description is very concise at two sentences, front-loading the core purpose. However, the second sentence about list_bundles could be considered tangential. It earns its keep by being extremely efficient, though it omits important context.

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?

Given the tool's complexity with 6 parameters, no annotations, and an output schema, the description is insufficiently complete. It does not explain the required dependency of hip_cm on sex, nor does it describe the output format or any behaviors. The bare-minimum description does not adequately compensate for missing annotation details.

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?

The input schema covers 100% of parameters with detailed descriptions, including units, locations, and defaults. The description adds no additional meaning beyond the schema, such as clarifying the relationship between hip_cm and sex. With full schema coverage, a baseline score of 3 is appropriate.

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?

Description clearly states that the tool calculates body fat percentage using the US Navy circumference method, which is a specific, well-known technique. This effectively differentiates it from other body fat calculators like calculate_body_fat, providing a clear verb and resource.

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 description provides no guidance on when to use this tool versus alternatives. The reference to list_bundles for related 'sante' calculators is vague and does not explain when this specific method is preferred over others, such as the standard body fat calculator or BMI.

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