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

Annotations already cover read-only, idempotent, closed-world safety profile. The description adds meaningful context beyond that: the underlying formula, the two optional calculation methods, and that output includes daily targets for weight change. It doesn't detail rate limits or side effects, but none apply.

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 plus a reference URL, front-loaded with the core definition. No obvious filler, though the URL and marketing tone ('Get yours') are slightly extraneous.

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 10-parameter, no-required-argument calculator with full schema coverage and annotations, the description covers purpose and hints at outputs (maintenance calories and daily targets). Without an output schema, exact return fields are not fully specified, but enough context is provided to invoke correctly.

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 all 10 parameters (units, sex, activity, etc.) are documented in the schema. The description adds no extra syntax or meaning for specific parameters, so 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?

States a specific calculation (maintenance calories via BMR × activity factor) and the methods/targets it provides. It doesn't explicitly differentiate itself from sibling bmr_calculator or calorie_deficit_calculator, but the resource is clear.

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?

Implies usage by describing what it computes for weight maintenance and gain/loss targets, but gives no explicit when-to-use or when-not instructions and does not route the agent to alternatives like bmr_calculator or calorie_deficit_calculator.

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