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, and it discloses nothing: not whether `value` is scored against the distribution in `values`, what shape `values` takes, or whether the result is a rank, a percentage, or an interpolation method.

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?

It is only two words repeated, so there is no padding, but this is under-specification rather than conciseness. Nothing is front-loaded because nothing is said.

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 annotations, no output schema, and a tautological description, an agent lacks everything needed to call a statistical tool correctly — particularly the meaning and format of `value` versus `values` and the rank output convention.

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 100%, so per the scoring baseline the schema does the documented work. However, both schema strings are generic placeholders ('Value to process', 'Values to process'), and the description adds no clarification of how the singular `value` relates to the `values` set.

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 'Percentile Rank: Percentile Rank', a tautology that merely restates the tool name. It gives no verb or resource beyond the identifier, and it does nothing to distinguish this tool from the nearly identical sibling x402-percentile-rank-of.

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 mention of alternatives such as x402-percentile-rank-of, x402-percentile, x402-percentile-rank-of, or x402-quartile. An agent has no basis for choosing among them.

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