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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so safety is covered. The description adds genuinely useful context by naming the exact equation used, which explains the computation. It does not disclose edge cases (e.g., formula limits by age/sex), but an output schema exists, so return detail is not required here.

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 and method, then the return. No wasted words. Every clause earns its place.

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 deterministic calculator, the definition is essentially complete: annotations cover the safety profile, the schema fully documents the four inputs, and an output schema handles the return shape. The only missing piece is explicit routing guidance versus adjacent health 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% — all four parameters (weight_kg, height_cm, age, sex) are documented in the schema with ranges and an enum. The description adds no additional parameter meaning, 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?

Names a specific verb (Calculate) and resource (Basal Metabolic Rate) and even specifies the method (Mifflin-St Jeor), which meaningfully distinguishes it from siblings like calculate_bmi or calculate_tdee. It stops short of explicitly contrasting those siblings, but the formula pinpoints the exact calculation.

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 implies its own use case through the resource name but offers no explicit when-to-use or when-not conditions relative to calculate_tdee, calculate_bmi, or calculate_ideal_weight. The 'see list_bundles' line is a discovery pointer rather than usage guidance, leaving the agent to infer applicability.

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