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

With no annotations, the description carries full burden and does well: it discloses the output fields, pricing model ($0.01 per call, USDC on Base), and input parameters. It does not discuss rate limits or error behavior, but is transparent about the data returned.

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 repetitive: 'EV charging stations worldwide from Open Charge Map' appears twice, and the list of returned fields is duplicated. It could be more concise without losing information.

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 tool with 4 parameters, no output schema, and no annotations, the description covers the return fields adequately but lacks details on output structure, pagination, and error conditions. It is reasonably complete but has gaps.

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%, so baseline is 3. The description adds only that the distance is in 'km' and max results is 'max stations', which is already in the schema. No significant new meaning is added beyond what the schema provides.

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 clearly states the tool's function: to return nearby EV charging stations given a location and radius, with specific fields like operator, connector type, power, points, and status. It mentions the data source (Open Charge Map) and worldwide coverage, making the purpose unambiguous.

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 says 'For routing, fleet and trip-planning agents', which gives a high-level context but does not explicitly state when not to use the tool or compare it to alternatives. Since no sibling tools perform a similar function, the guidance is adequate but minimal.

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