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. It only says 'convert', omitting whether the result is a string, how precision is handled, or whether this is a pure read-only operation. The behavior is underspecified.

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 extremely short and front-loaded, which is appropriate for a simple utility. However, it is under-specified rather than efficiently concise, offering no structure or additional essential context.

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 tool definition is incomplete: it lacks an input mechanism for the seconds value, describes no return format, and provides no examples. An agent cannot confidently select or correctly invoke this tool based on the available information.

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 declares 0 properties, yet the tool's name and description both imply a 'seconds' value is required. No parameter exists to supply it, and the description does not explain how the seconds are provided. This is a critical semantic gap that the empty schema does not resolve.

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 clear action ('Convert seconds to human'), but 'human' is vague and essentially restates the tool name. It does not specify the output format or distinguish this from sibling tools like x402-duration-humanize or x402-time-ago.

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 guidance is provided about when to use this tool versus the many related duration/time formatting tools. There is no mention of alternatives, exclusions, or context in which this conversion is appropriate.

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