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 method name, which does signal the underlying formula and its accuracy profile, but that largely restates the tool name and gives no further behavioral context (e.g. that hip measurement becomes mandatory for one sex).

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?

Two short sentences with the purpose front-loaded and no filler. The second sentence about list_bundles is a slight tangent but costs little and may aid discovery.

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, annotations cover the safety profile, and the schema fully documents all six inputs. Combined with a clear purpose statement, an agent has everything needed to invoke the tool correctly.

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 100%, with each of the six parameters documented including units, measurement sites, defaults and the female-only requirement for hip_cm. The description adds no parameter meaning beyond the schema, so the baseline 3 applies.

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 (Calculate), resource (body fat percentage) and qualifying method (US Navy circumference), so an agent knows exactly what is computed. It does not, however, distinguish itself from the closely-named sibling calculate_body_fat, leaving the agent to guess which body-fat tool to pick.

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 only guidance is 'See list_bundles for related sante calculators', which is a discovery pointer rather than a when-to-use statement. There is no mention of when the Navy method is preferable to calculate_body_fat, calculate_bmi, or calculate_waist_hip_ratio, and no prerequisites such as needing hip_cm for females.

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