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

Annotations already declare readOnlyHint, idempotentHint and closed-world behavior, so the safety profile is covered. The description does add one genuinely behavioral fact beyond the schema - results are 'never set below safe minimum intakes' - but says nothing about unit-pair resolution, rounding, or what happens when the goal weight is unreachable at the chosen rate.

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 short, but the opening is a verbless fragment ('Your maintenance calories, a daily target... and the weeks to your goal weight') that takes a second read to parse. Roughly half the text is a promotional 'Web page:' URL that does not help an agent decide or invoke anything.

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?

With no output schema, the description usefully enumerates the three returned values, which is the right move. However, for a 12-parameter tool with four metric/imperial duplicate pairs and a unit switch, it never explains how the two measurement systems interact or which inputs are ignored when a unit mode is chosen - a real gap for correct invocation.

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% (12/12 params documented), so the schema already carries parameter meaning. The description only echoes the rate range (0.25-1 kg / 0.5-2 lb) and adds nothing about the cm/ft/inch and kg/lb duplicate pairs or how `units` selects between them. 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?

Names the resource and the concrete outputs (maintenance calories, a daily deficit target, weeks-to-goal), which is more specific than a bare title restatement. It does not differentiate from close siblings such as tdee_calculator or bmr_calculator, both of which also produce maintenance/calorie figures, so an agent must infer the boundary.

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?

There is no when-to-use or when-not-to-use guidance, and no sibling is named as an alternative despite a very crowded calorie/BMR/TDEE family. The only implied use case (weekly weight-loss planning) comes from the output description, not from routing guidance.

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