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, yet it discloses nothing: not the return shape, not what input format is accepted, not how ambiguity is resolved. It is a pure label with no behavioral content.

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 is achieved by duplicating the name twice rather than by conveying information. No useful content is front-loaded because there is no useful content at all.

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 tool with no annotations, no output schema, and an unspecified input format, the description is far too thin. An agent does not know what string format 'value' expects (a four-digit year, an ISO date, a numeric year), which is exactly the detail this description should supply.

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?

With a single parameter at 100% schema description coverage, the baseline is 3 per the rubric. However, the schema text ('Value to process') is itself generic and the description adds nothing about whether the value is a year, a date, or an epoch, so this is a bare-minimum baseline rather than a value-adding one.

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 is 'Is Leap Year Num: Is Leap Year Num' – a verbatim restatement of the tool name with no added information. An agent can guess the tool checks leap years from the name, but the description itself contributes nothing to distinguish it from siblings such as x402-is-leap-year.

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 when-to-use guidance, no mention of prerequisites, and no routing to the near-identical sibling x402-is-leap-year. The description offers zero usage context.

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