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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it discloses nothing: it doesn't state how the timestamp is supplied, what the output looks like, what timezone is used, or whether milliseconds are handled. The empty input schema combined with this description leaves the tool's actual behavior completely opaque.

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 description is short but this is under-specification rather than conciseness — it repeats the tool name in sentence form and omits all operational detail. Every word is wasted on restating what the name already conveys.

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?

The description is severely inadequate. A tool with zero parameters and no annotations needs at minimum to explain how its input is obtained (e.g., 'converts the current Unix timestamp' or 'input provided via conversation context'), what format the result uses, and timezone/unit handling. None of this exists, so an agent cannot correctly select or invoke this 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?

Although the 0-parameter schema baseline is 4, this tool's described function inherently requires an input timestamp to convert, yet the schema has no parameters. The description does nothing to resolve this contradiction or explain where the input comes from, making correct invocation impossible to determine.

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 'Convert unix to date' is essentially a restatement of the tool name 'x402-unix-to-date' — it names the conversion direction but adds no new information. It never defines what 'unix' means (seconds vs milliseconds) or what 'date' output format is expected, and it does not clarify how this differs from sibling tools like x402-epoch-to-date or x402-unix-to-iso.

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 on when to use this tool versus the many overlapping date/time siblings (x402-epoch-to-date, x402-unix-to-iso, x402-date-to-unix, x402-timestamp-pretty). An agent has no basis for selecting this over an alternative with a nearly identical purpose.

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