Get vehicle telemetry

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

With no annotations present, the description carries the full disclosure burden and does well: it reveals a 15-minute server-side cache, the 15-minute staleness threshold behind isStale, and the automaker-supplied oemUpdatedAt origin. It omits auth or rate-limit behavior, which keeps it short of a 5.

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 sentences, zero filler, with the core action and return content front-loaded before the cache/refresh caveat. Every sentence contributes new 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?

There is no output schema, and the description compensates by explaining what the returned signals carry (oemUpdatedAt, isStale) and what the cache means for freshness. An agent can call this correctly and interpret the response from the description alone.

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 description coverage is 100%, so the baseline is 3, but the description goes beyond the schema by advising that most calls should leave refresh false and tying refresh to the cache it bypasses. It adds genuine decision guidance rather than restating the schema text.

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 names a specific verb and resource (fetch the latest telemetry snapshot for one vehicle) and enumerates the signal classes it returns (windows, odometer, fuel, battery). That content list cleanly separates it from siblings such as get_vehicle_location and get_vehicle_capabilities without the agent needing to open any schema.

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 gives clear, prescriptive guidance on the refresh parameter ('most calls should leave it false'), but that is parameter usage rather than tool selection. It never states when to prefer this tool over get_vehicle_location or get_vehicle_capabilities, leaving the agent to infer the choice from the signal list.

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