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

No annotations are provided, so the description carries the full burden of behavioral disclosure, and it discloses nothing. There is no mention of how the tool computes the perimeter, what assumptions it makes, what it returns, or how the empty input schema is handled — an agent cannot anticipate the tool's actual behavior in any way.

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?

The description is short but this is under-specification, not conciseness — it repeats the tool name twice in a "label: value" pattern that carries no information. Every word is wasted; the two tokens add nothing over the name itself.

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?

This is completely inadequate for an operational tool. With no parameters, no output schema, no annotations, and a tautological description, an agent has no way to know what inputs to conceptualize, what output to expect, how it differs from sibling geometry tools, or what edge cases exist. Every piece of information an agent would need is absent.

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?

The input schema has zero parameters, which sets the baseline at 4 — there is nothing for the description to document. That said, the description adds no meaning whatsoever, and the empty schema is itself surprising for a perimeter calculator that logically would need side count and side length; the description does nothing to clarify this oddity.

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?

The description "Regular Polygon Perimeter: Regular Polygon Perimeter" is a pure tautology — it merely restates the tool name with no verb, no resource, and no explanation of what the tool computes. An agent learns nothing about the function beyond what the name already implies, and it cannot be distinguished from siblings like x402-regular-polygon-area or x402-triangle-perimeter.

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?

The description offers zero guidance on when to use this tool versus any of its siblings. With hundreds of related geometry tools (x402-regular-polygon-interior, x402-regular-polygon-exterior, x402-triangle-perimeter, x402-trapezoid-perimeter, etc.), no conditions, exclusions, or alternatives are mentioned.

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