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 states the conversion direction but does not mention unit conventions, precision/rounding, value ranges, read-only safety, or what happens with invalid or missing input. The empty input schema compounds the ambiguity. The description provides the basic operation but not enough behavioral context for a zero-annotation tool.

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, with no wasted words. It states the conversion operation in one sentence. However, it sacrifices meaning for brevity: 'Convert kph to mps' adds little beyond the title and does not earn its place as a genuine explanation.

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 is conceptually simple, but the empty input schema and absent annotations mean the description must explain how the agent is supposed to invoke the conversion. It does not state what input the tool expects, how the value is passed, or what output format to anticipate. Among hundreds of sibling conversion tools, this description provides only the bare conversion direction and leaves key invocation details unspecified.

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?

Schema coverage is 100%, but the schema exposes zero parameters, which means the agent cannot know how to supply the value to convert. The description also does not document where the kph value comes from. Under the rubric, 0 params earns a baseline of 4; the description's explicit statement of the kph-to-mps conversion direction prevents this from scoring higher, and the missing input mechanism prevents a 5.

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 kph to mps' identifies the operation (a unit conversion from kilometers per hour to meters per second) with a specific verb and resource, so it is not a pure tautology. However, it merely restates the tool name 'Kph To Mps' without adding scope, precision, or differentiation from the many sibling conversion tools. The name and description are nearly identical, so the description adds minimal value.

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?

The description gives no guidance on when to use this tool rather than any of the numerous speed-conversion siblings such as x402-kph-to-knots, x402-mps-to-kph, x402-mph-to-mps, x402-speed-convert, or x402-units-convert. There are no use-case examples, prerequisites, or exclusions. Context implies the tool handles one conversion direction, but the agent is left to infer that without explicit routing.

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