calculate_distance

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

The description discloses a payment requirement ($0.001 USDC via x402), which is a useful behavioral trait, but it omits critical details such as input expectations, units, precision, whether it performs a network call, or what the result looks like. With no annotations provided, the description carries the full burden and falls far short.

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 a concise single sentence with no filler words. It front-loads the tool name and includes a cost note. However, the brevity is partly due to under-specification rather than efficient delivery of useful content, so it earns a high but not perfect score.

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 has no specific input schema, no annotations, and no output schema, yet the description provides almost no contextual information. It fails to clarify the domain (geometry, geography, or other), units, required inputs, or relationship to sibling tools like distance_2d. This is completely inadequate for reliable tool selection and invocation.

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 schema description coverage is reported as 100%, the schema only defines a generic 'params' object with no tool-specific property details. The description does not compensate by explaining what parameters calculate_distance expects (e.g., coordinates, points, units), so the agent has no meaningful semantic information beyond the name.

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 essentially restates the tool name ('calculate distance') and adds only a generic category label and cost. It does not specify what kind of distance is calculated (e.g., Euclidean, geographic, driving) and does not distinguish this from sibling tools like distance_2d or geolocate_ip. This is closer to a tautology than a clear functional statement.

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 usage guidance is provided. The description offers no context about when to use calculate_distance versus alternatives, no prerequisites, and no examples. The only additional information is the cost and category, which do not help an agent decide when to invoke this tool.

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