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: no input format, no return shape, no edge-case behavior (e.g. empty or single-value input), no idempotency or cost notes.

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 very short, but the brevity reflects under-specification rather than efficient structure — the single repeated phrase conveys zero information. Not verbose, but no sentence earns its place.

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 statistics tool with no annotations, no output schema, and a vague single parameter, the description is completely inadequate; an agent has no basis to construct a valid call beyond guessing the input format.

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?

With one parameter and 100% schema description coverage, the baseline is 3 even though the description adds no parameter meaning. The schema's own field text ("Values to process") is itself generic and gives no format guidance, so this sits at the baseline rather than above it.

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 "Range Stat: Range Stat" merely restates the tool name with no verb, resource, or scope. An agent cannot tell what statistic is computed (range? min/max spread?) or how this differs from the many nearby siblings such as x402-range, x402-range-statistic, x402-stats, or x402-quartile-deviation.

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 indication of when to use this tool versus the numerous overlapping sibling statistics tools, nor any prerequisite or input-shape guidance. Nothing in the text helps an agent choose correctly.

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