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

With no annotations, the description carries the whole burden. It does disclose one behavioral fact beyond the schema — 5 free trial calls per signed wallet, implying payment/auth handling — but says nothing about the formula used, expected units, numeric precision, or output shape for a numeric computation tool.

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, so nothing is bloated, but the first clause merely repeats the title and the second is a marketing/pricing tagline rather than useful tool information.

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?

The tool is mathematically simple and has no output schema, but the complete absence of parameter semantics (0% coverage, string-typed numerics) and units means an agent cannot reliably invoke it. Nothing compensates for those gaps in the description.

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% and all three parameters are untyped strings, so the description should explain what height, radius1 and radius2 mean. It mentions none of them, leaving ambiguous which radius is which, what units are expected, and whether values are parsed as 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?

"Volume of frustum" names the resource and computed quantity, but it is essentially a restatement of the tool name and gives no way to tell it apart from the near-identical sibling x402-cone-frustum-volume (or x402-prism-volume, x402-tube-volume). An agent cannot infer from the text whether radius1/radius2 are the two base radii or something else.

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 prerequisites, and no named alternative among the very large set of overlapping geometry-volume siblings. The only extra sentence concerns free trial calls, which is billing context rather than usage guidance.

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