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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and external-source profile is covered. The description adds only the id format, which is already in the schema, and says nothing about the returned record; no contradiction with 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?

A single front-loaded sentence with an inline example and zero filler. It is efficiently sized, though the example simply restates the schema's own example.

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 one-parameter getter with an output schema and read-only annotations, the description says enough to invoke it correctly: what it returns and the exact key format. The only real gap is routing guidance versus its sibling search/facets tools.

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% and the schema documents the identical id format, so the description adds no meaning beyond the structured field. Baseline 3 for a fully documented parameter set.

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 resource (vehicle listings dataset record) and a retrieval key (by id), which distinguishes it from the search/facets siblings. It does not explicitly name those siblings, so it falls short of a 5, but an agent can tell this is a single-record lookup.

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 the id format but no when-to-use guidance, no conditions, and no reference to the sibling tools (search, facets, price_history) that would tell an agent when to prefer this over them. Usage is only implied by the name.

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