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

No annotations are provided, so the description carries the full behavioral burden. It discloses the computation and a payment note ('5 free trial calls per signed wallet'), but says nothing about required vs optional inputs, validation of non-numeric strings, or error behavior. For a 3-param tool with zero annotation coverage this is thin.

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?

One compact sentence with the core purpose front-loaded. The trailing promo emoji text is minor noise but does not obscure the meaning.

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?

With no output schema, no annotations, and three undocumented string parameters including a duplicated-looking 'n'/'sides' pair, the description does not supply enough to call the tool confidently. It should at minimum clarify which inputs are required and what 'n' means.

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 coverage is 0% and the description only vaguely maps to two of the three parameters ('side length and number of sides'). The third parameter 'n' is never explained, and the relationship between 'n' and 'sides' - both plausibly the number of sides - is left ambiguous, which is a real risk of wrong invocation.

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 and resource: 'Returns the perimeter of a regular polygon from its side length and number of sides'. That is unambiguous against sibling perimeter tools like triangle-perimeter. It does not, however, distinguish itself from the close sibling x402-regular-polygon-area, which shares the same inputs.

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 and no mention of alternatives such as x402-regular-polygon-area or the exterior/interior angle siblings. The agent must infer selection purely from the name.

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