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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety and side-effect profile is fully covered by structured data. The description's only added behavioral content is what the listing contains (inputs, government sources); it says nothing about pagination, filtering behavior, or whether the catalogue is static.

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 well-formed sentence that front-loads the verb and resource and packs in the return contents without a wasted word.

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 discovery tool with no output schema, the description does the necessary work of saying what the catalogue entries contain, and annotations cover the safety profile. The remaining gap is the opaque free-form 'query' parameter, which is left entirely to the schema.

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?

There is a single optional 'query' object with 100% schema description coverage, so the schema already documents the parameter. The description does not explain what keys the query object accepts or how filtering works — useful information given additionalProperties allows arbitrary keys — so it adds no meaning beyond the schema. Baseline 3 applies.

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 gives a specific verb ("List") and resource ("the vehicle checks this service offers") and goes further to state what each entry contains: inputs and government sources. That clearly separates it from the sibling check-performing tools (vehicle_check_clean_air, vehicle_check_fleet, vehicle_check_road_legal), though it never names an alternative explicitly.

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 listing framing implies a discovery use case — call this to learn what checks exist before calling a check tool — but there is no explicit when-to-use statement, no condition, and no named alternative such as vehicle_check_road_legal. Usage is inferable rather than stated.

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