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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely non-structured context: it is a screening/risk-check tool, not a diagnostic or treatment tool, and it is scoped to adults. It still says nothing about what the result conveys (cutoff values, ratio interpretation), which would be the next useful disclosure.

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 sentences, front-loaded with the trigger condition and closed with the exclusion list. The inline example phrases are slightly verbose but they do real routing work, so the length is justified.

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 read-only, closed-world tool with no output schema, the description covers who it applies to, what questions it answers, and what it must not be used for. The only real gap is that it never indicates what the returned assessment contains or whether height is optional for a waist-only check.

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% and the schema even explains the measurement protocol (at the belly button, after breathing out), so the baseline is 3. The description's examples hint at the cm/inch and waist-to-height variants but add no unit, range, or requiredness information beyond the schema.

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 states a specific resource and scope: evaluating whether an adult's waist/belly size is risky, with concrete query examples. It never names the sibling waist_target, so an agent must infer the boundary between 'check my waist' and 'what should my waist be' from the names alone.

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?

It gives explicit when-to-use triggers with four representative phrasings and an explicit when-not-to-use list (children, pregnancy, disease diagnosis, treatment/medication). This is exactly the routing information an agent needs, leaving little to inference.

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