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

With no annotations provided, the description carries the full burden of disclosing behavior, but it reveals nothing beyond the name. It does not state whether it reads data, mutates state, computes a value, or what output to expect.

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 extremely short but not concise in a useful way; it is under-specified and internally redundant ('Trapezoid Perimeter: Trapezoid Perimeter'). No information is front-loaded because there is no information at all.

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?

Given the lack of annotations, output schema, and parameter details, the description needed to explicitly state that this tool computes a trapezoid perimeter. It does not, leaving the agent to infer behavior solely from the tool's name, which is unreliable in a large sibling list.

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, so there is nothing to explain about parameter syntax or meaning. Per the baseline rule for 0-parameter tools, the description need not compensate for missing parameter docs. The empty schema already fully represents the parameter surface.

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 is 'Trapezoid Perimeter: Trapezoid Perimeter', which merely restates the tool name and title without adding any verb or functional detail. It does not explicitly say the tool calculates or returns a trapezoid perimeter, nor does it distinguish itself from siblings like x402-trapezoid-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?

There is no guidance on when to use this tool versus alternatives. No mention of comparison tools, use cases, or conditions under which this tool is preferred.

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