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

With no annotations, the description carries the full burden of behavioral disclosure, and it discloses nothing. It does not state which week-numbering convention is used (ISO 8601 vs. calendar week), what the output looks like, or any edge-case behavior. The description is a label, not a behavioral specification.

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?

The text is short, but this is under-specification rather than conciseness. There is no front-loaded information because there is no information at all - the two-word phrase cannot be said to earn its place any more than an empty string would.

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 1-param tool with no output schema and no annotations, the description is still required to state what it computes. An agent cannot determine the input format, the week-numbering convention, the return shape, or how this differs from x402-week-of-year and x402-iso-week. The definition is completely inadequate.

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 100%, so the baseline is 3. The description text itself adds nothing about the date parameter, and the schema line "Date to process" is generic but does convey the parameter's role. However, neither the description nor the schema specifies the expected date format or how the week number is derived from 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 "Week Number: Week Number" is a pure tautology that merely restates the tool name. It contains no verb, no resource, and no behavioral claim, so an agent cannot tell what the tool computes. With siblings like x402-iso-week, x402-week-of-year, and x402-calendar-weeks nearby, this description provides zero differentiation.

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?

No usage guidance of any kind is provided - no when-to-use context, no exclusions, and no mention of alternatives such as x402-iso-week or x402-week-of-year. The description is not actively misleading, but it leaves all selection decisions to the agent with no support.

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