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. It reveals no input expectations, no output format, no edge-case behavior, and notably does not explain how a 0-parameter tool can receive the dataset presumably needed to compute quartile deviation.

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?

Two words is under-specification, not conciseness. The sentence 'Quartile Deviation: Quartile Deviation' does not earn its place—it supplies zero information beyond what the tool name already conveys, so it fails the front-loading and value-per-sentence test.

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?

For a statistical tool sitting among dozens of near-identical statistical siblings, this definition is completely inadequate. An agent cannot determine what the tool computes, when to select it over x402-quartile or x402-iqr, how it receives input (the 0-param schema is anomalous), or what it returns—with no output schema or annotations to fill the gaps.

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 schema has 0 parameters, so per the rubric the baseline is 4: there is structurally nothing for the description to document, since the empty schema is already complete. The description adds no parameter meaning, but it is not penalized heavily because there are no parameters to compensate for.

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 a pure tautology—"Quartile Deviation: Quartile Deviation" merely restates the tool name with no verb, action, or resource described. It never states what the tool does (e.g., computes, calculates, returns), and provides zero differentiation from closely related siblings like x402-quartile, x402-iqr, or x402-midhinge.

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 whatsoever on when to use this tool versus the many adjacent statistical tools in the sibling list (x402-quartile, x402-iqr, x402-interquartile-mean, x402-midhinge, x402-five-number-summary). No context, no exclusions, no alternatives are mentioned.

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