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

No annotations are provided, so the description carries the full burden. It makes clear this is a pure computation (max minus min) with no implication of state changes, which is reasonable for a trivial stateless math tool, but it does not explicitly confirm read-only/stateless behavior or describe the return shape.

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 short sentences, front-loaded with the operation and formula. Only minor redundancy ('Range:' restating 'statistical range'), otherwise no wasted text.

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 trivial one-parameter tool with full schema coverage and no output schema, the definition is close to adequate, but it never clarifies the input format (comma-separated string vs. JSON array), which matters given the string-vs-array mismatch between description and schema.

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 coverage is 100%, so the single parameter is already documented, giving a baseline of 3. The description's 'Provide values array' adds no format or syntax detail beyond the schema, and actually introduces mild confusion by calling it an array while the schema types it as a string.

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?

States a specific verb and resource ('Calculate the statistical range of a dataset') and even gives the formula ('maximum minus minimum'), making the operation unambiguous. However, it does nothing to distinguish itself from near-identical siblings such as x402-range-stat and x402-range-statistic, leaving the agent unable to route between them.

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 statement of when to use this tool versus alternatives like x402-range-stat, x402-iqr, or x402-midrange, and no preconditions or exclusions. The agent must infer usage purely from the name.

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