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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, and the description does not contradict them. It adds crucial behavioral context: detail_url must be shown as a clickable link to the FINN configurator, vehicle_id is an internal identifier that must never be displayed, and checkout URL construction is forbidden. This goes well beyond the structured 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?

Four sentences, each earning its place: the first states the tool's purpose, the second explains where the vehicle_id comes from, and the final sentences provide critical display and delegation rules. There is no filler or redundant repetition of schema details.

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 single-parameter, read-only tool with no output schema, the description is remarkably complete. It covers the tool's purpose, parameter source, relationship to sibling tools (especially get_subscription_pricing), and user-facing display constraints. An agent has enough information to invoke and handle the tool correctly.

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 input schema provides 100% coverage for vehicle_id with a pattern, max length, and example. The description adds meaning by stating that the ID comes from search_vehicles results and is an internal API identifier that should not be displayed to users, which is valuable but not fully transformative given the schema's completeness.

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 begins with a specific verb and resource: 'Get full specifications, equipment, all images, and pricing per term for a specific vehicle.' This clearly distinguishes it from siblings like search_vehicles and get_subscription_pricing, which handle discovery and pricing link generation respectively.

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?

Explicit guidance is provided: 'Use a vehicle_id from search_vehicles results.' It also states when to call get_subscription_pricing for checkout links and includes an explicit prohibition: 'Never construct checkout URLs yourself.' This establishes clear use boundaries between this tool and related tools.

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