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. It does not state the supported number range, language of the output words, handling of negatives/decimals, or the output format. An agent cannot anticipate edge-case behavior.

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 terse, but brevity here represents under-specification rather than purposeful conciseness. It omits essential invocation and behavioral details that an agent needs.

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?

Given no annotations, no output schema, and an empty input schema, the description is the only information source. It is insufficient for an agent to call the tool correctly, as the input mechanism is undefined.

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 is empty, yet the tool clearly requires a number to convert. The description does not explain how the number is supplied, leaving the invocation impossible to determine from the definition alone. This is a critical gap that the description should have compensated for.

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 uses a specific verb ('convert') and resource ('number to words'), making the core function clear. It does not explicitly differentiate from related siblings like x402-number-humanize or x402-to-roman, but the target transformation is understandable.

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 on when to choose this tool over alternatives such as x402-to-roman, x402-number-humanize, or x402-number-base. The description gives no usage context, prerequisites, or exclusions.

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