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

Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description does add genuinely useful cost disclosure ('Cost: 1 credit') and enumerates the derived metrics produced. It stops short of describing partial-result behavior when the optional BMR/TDEE inputs are absent, which is the one behavioral wrinkle an agent would care about.

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?

It is a single sentence, which is efficient, but it opens with a redundant 'BMI Calculator: BMI Calculator computes Body Mass Index' restatement of the name and title. The credit-cost note is correctly placed at the end but buried in parentheses rather than front-loaded.

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?

An output schema exists, so return values need not be spelled out, and the description enumerates the computed metrics at a high level. For a six-parameter read-only calculator this is nearly complete; only the conditional-dependency behavior of the optional inputs is left unaddressed.

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%, and every parameter already carries a description and example, so the schema does the heavy lifting. The description adds no unit conventions or input constraints beyond what the schema states. Baseline 3 is the correct ceiling here.

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 gives a specific verb ('computes') and enumerates the concrete outputs: BMI, ideal weight ranges, BMR, TDEE, calorie targets and macros. It is clearly distinguishable from nearby siblings like MathCalculator or UnitConverter, though it never explicitly contrasts itself with those tools and the opening restates the name and title verbatim.

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?

'for fitness and health applications' is the only contextual scoping, and it is too generic to route an agent. There is no statement of when to prefer this over Nutrition, AgeCalculator or UnitConverter, and no explicit note that omitting age/gender/activityLevel yields a BMI-only result.

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