List vehicles

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 does disclose the read-only nature implicitly via 'List' and enumerates the returned fields. It omits permission/auth requirements and the behavior when the account has no connected vehicles (empty list vs error), which matters for a tool with zero annotation coverage.

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?

Three short sentences, front-loaded with the resource and the return payload, then the follow-up instruction. No filler.

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 zero-parameter read tool with no output schema, the description supplies the return field summary that the schema cannot, plus the chaining hint. Only the empty-result/auth edge cases are unaddressed, which is a minor gap.

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 takes no parameters, so the baseline is 4. The description adds useful cross-tool context by explaining the semantic value of the returned id as vehicle_id for downstream tools.

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 and resource ('List the user's Smartcar-connected vehicles') plus the exact fields returned. This clearly separates it from siblings like get_vehicle_telemetry, get_vehicle_capabilities, and the lock/unlock tools, which operate on a single vehicle.

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?

Explicitly tells the agent to use the returned id as the vehicle_id argument to other tools, which establishes this as the entry point for the vehicle tool family. It stops short of naming which sibling to call next or stating when not to call it, but the chaining guidance is clear.

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