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

No annotations are present, so the description carries the full disclosure burden. It confirms the operation is a pure read/calculation and discloses the default-year behavior and the payment/trial model ('5 free trial calls per signed wallet'), but says nothing about error handling, output type (integer 52/53), or rate limits beyond the trial count.

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 compact clauses front-load the core behavior before the payment note. The emoji/trial-call content is slightly promotional but relevant to the x402 payment context, and the opening 'Weeks In Year:' restates the tool name with no added value.

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 single-optional-parameter, no-output-schema utility, the description covers what it returns and the default behavior sufficiently. The main omission is the concrete return type (e.g., integer count of 52 or 53), but this is a small gap for such a simple tool.

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 0%, so the description must explain the single parameter. It does add meaning by stating the year is optional and defaults to the current year, which the bare schema (type: string) does not convey. It stops short of specifying format (e.g., four-digit string), keeping it from a 5.

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 states a specific verb (returns) and resource (number of ISO weeks in a year), plus the default-to-current-year behavior. It is clearly distinguishable from adjacent tools like x402-week-number or x402-days-in-year, though it never names an alternative or sibling 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?

There is no statement of when to use this tool versus alternatives such as x402-week-number, x402-week-of-year, or x402-calendar-weeks. The only usage-like information is the default value, which is not the same as guidance on tool selection.

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