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

No annotations are provided, so the description carries the full behavioral burden, and it discloses nothing: no return format, no default behavior when the optional date is omitted, no format expectations. The name conveys nothing about the operation.

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 short, but the brevity comes from under-specification rather than economy — the single duplicated phrase earns nothing. Not verbose, but not usefully concise either.

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 date-to-weekday-name tool with no annotations and no output schema, the description should at minimum state the transformation and the accepted date formats. It provides none of that, leaving the agent unable to predict the response.

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?

The input schema has one parameter with 100% description coverage ('Date to process'), which sets the baseline at 3 by the coverage rule. The description adds no meaning beyond that, but with only one parameter and full schema coverage, the schema can do the heavy lifting.

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 'Day Name Full: Day Name Full' merely restates the tool name with a colon and adds no verb, resource, or outcome. It does not tell an agent that it returns the full weekday name (e.g. 'Monday') for a given date, nor does it distinguish itself from siblings like x402-day-name-short or x402-day-of-week.

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 guidance whatsoever about when to use this tool versus alternatives. The near-identical sibling x402-day-name-short is never mentioned, and no input conditions or prerequisites are stated.

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