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

With no annotations, the description carries the full behavioral burden and discloses almost nothing: no formula (v = f·λ), no unit conventions, no return shape. The sole behavioral statement is the commercial note about five free trial calls per signed wallet, which says nothing about what the tool does.

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 and front-loaded, so nothing is padded, but the brevity comes at the cost of substance and the first clause duplicates the tool name. The pricing badge is the only distinct information present.

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?

A unit-sensitive physics calculator with two undocumented parameters, no annotations and no output schema needs far more than one tautological line. The description omits the computation itself, which is the one thing the agent cannot derive from structured fields here.

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% for both parameters, so the description must compensate and does not. Frequency and wavelength are given no units (Hz vs rad/s, meters vs nanometers) and no format hints, leaving the agent to guess at a dimension-sensitive input.

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?

"Wave Speed: Speed of wave" restates the tool name rather than describing an operation. It never says it computes wave speed from frequency and wavelength, so the agent must infer the calculation from the parameter names alone.

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?

No when-to-use guidance and no mention of alternatives, even though siblings like x402-wavelength, x402-frequency, x402-velocity and x402-speed-convert exist in the same namespace. The only context offered is a pricing note about free trial calls.

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