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

No annotations, so the description carries the load; it does disclose that the result includes a neutral category classification and that the formula matches a known public calculator, implying deterministic, side-effect-free computation. It never explicitly states that nothing is stored or that the tool is a pure calculation, and it gives no detail on the returned category boundaries.

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 front-loaded sentence with the method and inputs, plus a short provenance clause; dense but every clause carries information. The formula-source sentence is the weakest earner but adds reproducibility value.

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?

For a 5-parameter calculation tool with full schema coverage and no output schema, the description supplies what is missing: what is computed, which method, and that a category classification is returned. Only the format of the category output remains unspecified, a minor gap.

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%, so the schema already documents each measurement including the conditional hip requirement for females. The description's enumeration of the same measurements adds no semantics beyond the schema, making the baseline 3 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?

States a precise verb and resource ('Körperfettanteil (%) ... berechnen') and names the exact method (US-Navy-Umfangmethode) plus the required measurements. It is clearly distinguishable from siblings like bmi or ffmi, though it never explicitly contrasts itself with them.

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 listed inputs imply when the tool applies (you need circumference measurements), but there is no explicit when-to-use/when-not guidance and no pointer to the alternative calculators (bmi, ffmi, idealgewicht) that share this domain.

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