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

With no annotations, the description carries the full behavioral burden. It implies a pure read-only calculation and mentions the wallet/trial gating, which is useful context, but says nothing about the returned value (a unitless ratio? a formatted number?), how the string-typed forces are parsed, or what happens with zero input force.

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?

A single sentence front-loads the definition and formula with no wasted wording. The trailing trial-call marketing and emoji add noise but consume minimal space.

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 simple two-parameter arithmetic tool with no output schema and no annotations, the definition covers the core operation but omits the return type and input validation behavior. Adequate to invoke correctly in the happy path, incomplete for edge cases.

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 0%, so the description must compensate. It does partially: the formula makes clear that outputForce is the numerator and inputForce the denominator, removing the main ambiguity. However, it says nothing about units, numeric format, or why both parameters are strings rather than numbers.

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 verb ('Computes') and the exact resource ('mechanical advantage'), plus the formula used (output force / input force), so an agent knows precisely what result to expect. It does not distinguish itself from nearby siblings such as x402-force, x402-efficiency or x402-work, but the name-plus-formula combination is unambiguous on its own.

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 guidance on when to prefer this over siblings (e.g. x402-force, x402-work) and no stated prerequisites or input constraints. The only contextual sentence is promotional ('5 free trial calls per signed wallet'), which informs billing, not tool selection.

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