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

With no annotations, the description carries the full burden and does meaningful work: it discloses the returned artifacts (TDEE, three deficit tiers, weekly loss, protein target) and a safety gate that suppresses numeric targets for minors or underweight users. It stops short of naming the underlying BMR formula or how activity factors are applied, which would matter for a health calculation.

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?

Three tight sentences, front-loaded with the computed output and followed by the constraint and the reference link. The website reference sentence is the least informative element but is short enough not to hurt.

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 5-parameter calculation tool with no output schema and no annotations, the description conveys what comes back and the key guardrail. The remaining hole is methodological detail (which BMR equation, how activity multipliers map) and undocumented body-measurement parameters.

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 coverage is only 40%: activity (default light) and age range are documented in the schema, but sex, height_cm and weight_kg have no descriptions anywhere. The description adds no unit, format or interpretation guidance, only an oblique reference to age/BMI via the adult gate, so it does not compensate for the gap.

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 names a specific computation: TDEE plus three named deficit tiers (−15/−20/−25 %), expected weekly weight loss and a protein target. That clearly separates it from siblings like grundumsatz (BMR only) or kalorienverbrauch, although no sibling is named explicitly.

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 use case (planning a calorie deficit) is implied by the content described, and the mention of a reference calculator gives context. However, there is no explicit statement of when to choose this over grundumsatz or kalorienverbrauch, and no prerequisites or exclusions beyond the adult gate.

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