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

No annotations are provided, so the description carries the full burden. It says nothing about precision, rounding, output format, or what happens on invalid input. For a pure conversion tool this is a minor burden, but nothing beyond the verb is disclosed.

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?

One short sentence, front-loaded with the operation. No wasted words, though it is arguably too terse given the missing behavioral detail.

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 trivial single-input converter with no output schema, the title-style description is functionally sufficient to call it. Precision and error behavior are absent but low-stakes, so 3 is the minimum viable score.

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?

One parameter named 'value' with schema description 'Value to process' – which contradicts the tool's purpose since the value is a measurement to convert, not something to 'process'. The description adds no syntax, range, or format guidance.

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?

States a specific verb (Convert) and resource (meters to yards) with unambiguous directionality. Siblings include x402-yards-to-meters, so specifying the direction is essential and it does so explicitly.

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 when-to-use or when-not-to-use guidance. In a family with both meters-to-yards and yards-to-meters plus x402-meters-to-feet, x402-metric-imperial, and x402-units-convert, an agent gets no routing help, though the tool name is self-explanatory.

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