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

No annotations are provided, so the description carries the full burden, but for a trivial deterministic math calculation the burden is light. The explicit formula implies a pure, side-effect-free computation, yet the description says nothing about expected input units (Hz) or output units (seconds).

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?

Very short and front-loaded: the name is expanded, the operation defined, and the input requested in one compact sentence. Slight redundancy between 'Period' and 'Calculate the period' but nothing wasted.

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 one-parameter calculator with no annotations and no output schema, the description is minimally adequate — it names the operation and the input. It leaves the agent guessing about units and the return representation, which matters for a physics quantity.

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?

One parameter with 100% schema description coverage, so the schema already labels it as 'Frequency to process.' The description's 'Provide frequency value' adds no unit, range, or format detail beyond the schema; 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?

States a specific verb (calculate) and resource (period of a wave) and even gives the formula (reciprocal of frequency), which implicitly distinguishes it from the sibling x402-frequency. It does not, however, explicitly name or contrast itself with that sibling, so it falls short of a 5.

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 mention of the obvious alternative (x402-frequency, x402-wavelength, x402-wave-speed). The agent must infer the reciprocal relationship itself.

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