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

With no annotations, the description carries the full behavioral burden. It usefully notes the pricing/trial model ('5 free trial calls per signed wallet'), which hints at an auth/payment requirement, but says nothing about what happens after the trial, error behavior on malformed input, or date-format expectations.

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?

A single front-loaded sentence plus a short promotional clause; nothing is buried. The emoji/trial text is minor noise but arguably relevant to the payment model.

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?

No annotations, no output schema, and three undocumented parameters with zero schema coverage leave large gaps. The description covers purpose and return type but not parameter usage or post-trial behavior, which an agent needs to invoke this correctly.

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 0% and the description does not explain any of the three parameters. The meaning of 'n' is completely opaque, and the expected format of 'date' (ISO? epoch?) and 'years' (integer string? signed?) is unspecified despite 0 required parameters.

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 ('Adds years to a given date or the current date') and the return type (ISO timestamp). The unit 'years' implicitly distinguishes it from sibling tools like x402-add-days and x402-add-months, but the description never names those alternatives explicitly.

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?

It does disclose the default behavior when no date is given ('or the current date'), which is a usable hint. However, it offers no guidance on when to prefer this over x402-add-days, x402-add-months, or x402-date-math, and no exclusions or prerequisites.

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