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

No annotations are provided, so the description carries the full behavioral burden. It discloses that the calculation uses WHO adult classification, which is useful context, but it does not explicitly describe the return values (e.g., BMI plus category) or any other behavioral traits.

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 two short sentences, front-loaded with the core purpose and followed by a useful reference. There is no filler or redundancy.

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 simple two-parameter calculator with complete schema coverage, the description gives enough context to invoke it correctly, including the WHO adult classification scope. The main minor gap is that it does not explicitly state what the tool returns, though the classification mention strongly implies it.

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 both weight_kg and height_cm documented as 'Gewicht in kg' and 'Größe in cm'. The description adds no parameter-level detail beyond the schema, so the baseline 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?

The description clearly states that the tool computes Body-Mass-Index (kg/m²) with WHO classification for adults, and references the corresponding online calculator. The verb is implicit in the calculator context, but the resource and scope are clear enough to distinguish it from siblings like ffmi or koerperfett_navy.

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 does not say when to use this tool versus the many sibling health calculators, nor does it give any exclusions or prerequisites. Usage is only inferable from the name and the mention of WHO classification.

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