lean_body_mass

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

With no annotations, the description carries the full burden of explaining behavior, but it only reveals that the tool costs $0.001 USDC via x402. It fails to disclose the operation's nature, required inputs, return value, or any side effects, leaving the agent without essential behavioral context.

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?

The description is very short, but the first clause merely repeats the tool name and the category is minimally informative. The cost clause is useful, yet the overall structure does not earn its place because it omits core functional details rather than being simply concise.

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?

Given no output schema, no annotations, and a generic params wrapper, the description is far from complete. It does not say what inputs are required, what output is produced, or how the x402 payment is initiated, making it nearly impossible for an agent to invoke the tool correctly without external knowledge.

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?

The schema has a single generic 'params' object with 100% description coverage, so the baseline is 3 per the rubric. However, the description adds no meaning about the actual parameters, and the schema's 'Tool parameters as JSON object' is unhelpfully generic, not naming fields like age, sex, height, or weight.

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 restates the tool name as a noun phrase ('lean body mass') and adds a generic category ('Health & Fitness tool'), but never states what the tool actually does, what it calculates, or what it returns. It does not distinguish this from sibling tools like body_fat_calc or ideal_weight_calc.

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 provides no guidance on when to use this tool versus alternatives, no prerequisites, and no context for selecting it. The only extra information is the payment cost, which does not help an agent decide when this tool is appropriate.

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