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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds only that a weight category is produced, and since an output schema exists, that is largely redundant. No extra behavioral context (rounding, category thresholds, unit assumptions) is offered.

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 short sentences, front-loaded with the core action, with no filler. The second sentence is a cross-reference to list_bundles rather than information about this tool, which is mildly off-purpose but still cheap and useful for routing.

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 full schema coverage, complete annotations, and an output schema, the description supplies everything needed to invoke it correctly. It stops short of 5 only because it gives no differentiation from the nearby BMI/BMR/body-fat calculators.

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 parameters (weight_kg, height_cm) fully described including units and minimums. The description adds no unit conventions, ranges, or edge-case handling beyond the schema, so the baseline of 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?

States a specific verb (Calculate) and resource (BMI) plus the derived output (weight category), which distinguishes it from adjacent siblings such as calculate_bmr, calculate_body_fat and calculate_ideal_weight. It never explicitly names those siblings, so differentiation relies on the agent's own reading of the tool list.

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 only guidance is 'See list_bundles for related sante calculators', which is a discovery pointer rather than a when-to-use rule. There is no statement of when this tool is preferable to calculate_bmr or calculate_body_fat, and no prerequisites or exclusions.

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