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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, covering the behavioral safety profile. The description adds no new behavioral information beyond what annotations provide, but it does not contradict them. The bar is lower here due to rich annotations.

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, information-dense sentence with an appended note about obtaining IDs. It is front-loaded and contains no fluff.

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 simple detail retrieval tool with one parameter and an output schema, the description fully covers what the tool returns and how to get the input. No gaps remain.

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 for the single parameter 'id' is 100%, and the schema description already includes an example and source guidance. The description does not add additional parameter semantics beyond what the schema provides, so it meets the baseline but does not exceed it.

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 uses a specific verb ('Get full details') and a concrete resource ('car listing by ID'), and lists the exact data fields returned (VIN, price, MSRP, etc.). It also explicitly references the sibling tool vehicle.carmarket.search as the source for listing IDs, distinguishing this tool from others.

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 clearly states when to use this tool (when you have a listing ID) and directs the user to the sibling tool for obtaining IDs. It does not explicitly exclude other use cases or mention alternatives, but the context is sufficiently clear.

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