vehicle_by_id

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 states that it returns current position, but does not disclose error behavior, authentication needs, or rate limits; adequate for a simple read tool.

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 sentence that includes examples, making it slightly longer but still clear and efficiently conveying essential 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?

Given the tool's simplicity (one parameter, no output schema), the description is fairly complete: it explains what is returned and how to identify the vehicle. It could optionally describe the return format, but that is often inferred.

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 schema already describes the parameter as 'Vehicle label, internal id, or entity id.' The description adds value by giving concrete examples (e.g., 'fleet number painted on the bus, or the entity id from a previous vehicles() call'), which helps the agent understand acceptable inputs.

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 explicitly states the verb 'Get' and the resource 'single vehicle's current position', with examples of acceptable identifiers, clearly distinguishing it from siblings like 'vehicles' which returns all vehicles.

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 implies usage when you have a specific vehicle id or label, but does not explicitly state when not to use or name alternatives like 'vehicles' or 'next_arrivals' for broader queries.

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