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

Annotations already establish the safe-read profile (readOnly, idempotent, non-destructive, closed-world), so the description only needs to add beyond that. It does add real value by disclosing the returned content (half-height figure and the Indian cutoff) and the scope exclusions, which is meaningful given there is no output schema. It does not say what happens when height is omitted, even though only sex is required.

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 trigger condition is front-loaded, followed by the output and then the exclusions in a single compact passage. The three example phrasings consume space but are doing routing work for natural-language queries. Little is wasted.

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 carries the burden of saying what comes back, and it does ('half your height and the Indian cutoff'). Exclusions are covered. The remaining gap is behavioral: only sex is required, so an agent is not told whether height is truly optional or what is returned without 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%, so the schema already documents sex, height_cm, height_ft and height_in, including the unit and the paired use of feet/inches. The description's examples imply the input shapes but add no syntax or validation detail beyond the schema. 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?

The description states a specific verb+resource: it returns a healthy waist-size target, computed as half the height plus the Indian cutoff. That is concrete and distinguishable from a check-style tool. It does not, however, name or contrast itself with the sibling waist_check, leaving that differentiation to inference.

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?

Usage context is given concretely through example queries ('healthy waist size for 5 ft 8 man', 'ideal waist for 160 cm woman'), and explicit exclusions are provided (children, pregnancy, medical diagnosis). What is missing is the alternative: it never says 'if the user already has a waist measurement, use waist_check instead', which is exactly the sibling it should route against.

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