calc_bmi

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, so the safety profile is covered without the description. The description adds nothing further: it does not say what is returned (a scalar BMI value), how units are handled, or what happens on invalid input, so it contributes no behavioral context beyond structured fields.

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?

A single short sentence with no filler and the key concept front-loaded. It is efficient, though its terseness is the source of the completeness gaps rather than a virtue in itself.

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?

With no output schema, the description should indicate what comes back (a numeric BMI, possibly a category) and the input unit contract; neither appears. For an arithmetic tool with annotations covering safety this is a modest but real omission.

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 0%, so the description carries the full burden of explaining the two parameters — and it says nothing about weight_kg or height_cm. The parameter names include unit suffixes (kg, cm) which mitigates the gap somewhat, but the description adds no meaning beyond those names.

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 names a specific verb (Calculate) and a specific, well-known metric (Body Mass Index), which distinguishes it cleanly from the other calc_* siblings such as calc_tip or calc_mortgage. It stops short of stating scope or output, but the purpose itself is unambiguous.

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?

There is no indication of when to use this over alternatives or any prerequisites (e.g., metric-only units, population applicability). For a single-purpose calculator this is a minor gap, but nothing in the text routes the agent.

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