list_vehicles

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

With no annotations, the description carries the burden of behavioral disclosure. It states what the tool returns (vehicles with first/last telemetry timestamp), which gives some transparency. However, it does not disclose whether the operation is read-only (likely but not stated), any performance implications, rate limits, or pagination behavior. For a simple list operation this is partially sufficient but not comprehensive.

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 single clear sentence that front-loads the primary action ('List every vehicle') and then specifies the key output detail. There is no redundant wording or filler. It is optimally concise for the information conveyed.

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 presence of an output schema means the return value structure is already defined, so the description need not explain it. The description adds the key detail of including first/last telemetry timestamps, which is useful for selection. However, it omits any mention of ordering, pagination, or limits, which could matter for large fleets, but for a simple list this is acceptable.

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 tool has zero parameters, so the schema description coverage is trivially 100%. According to the rubric, zero parameters justify a baseline of 4 because there is nothing for the description to explain about parameters. The description adds no parameter info, but none is needed.

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 verb 'List' and the resource 'every vehicle in the fleet', with the added detail of returning 'first/last telemetry timestamp'. This unambiguously distinguishes it from siblings like get_vehicle_telemetry (which targets a single vehicle) and fleet_health_summary (which provides summary metrics).

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 use this tool versus alternatives. The description does not mention any exclusions, prerequisites, or context where another sibling would be more appropriate. The agent must infer the use case solely from the purpose, which is a gap in routing decision support.

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