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

No annotations exist, so the description carries the full burden, and it discloses nothing: not the formula used, not unit handling (both inputs are strings), not whether values are parsed as numbers, and not whether the result is a scalar. It is implicitly a pure computation, but that is inference, not disclosure.

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 with zero padding, which is good, but the brevity comes from omission rather than efficiency — the single line is essentially a title restatement. Under-specification, not tight writing.

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 two-parameter compute tool with no annotations and no output schema, the definition is inadequate: the formula, expected input format (strings vs numbers), units, and result shape are all unstated. An agent cannot call this confidently without guessing.

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% (frequency, wavelength), so the baseline is 3 even though the description adds no parameter meaning. Worth noting the schema descriptions themselves are placeholders ("Frequency to process"), and the description misses the cheap win of stating v = f·λ, which would clarify how the two parameters relate.

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 with no additional specificity — no verb, no statement that it computes v = f·λ. It does identify the physical quantity, but tells an agent nothing it couldn't infer from the name x402-wave-speed.

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 guidance, no exclusions, and no reference to any alternative. With close siblings such as x402-speed, x402-velocity, x402-wavelength, x402-frequency and x402-doppler-frequency, the agent gets no help deciding which one applies.

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