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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds per-action input semantics but says nothing about result shape, pagination, `limit` behavior, or rate limits, which are the behavioral details an agent would still need.

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 dense paragraph that front-loads the resource and then walks the actions in dependency order; the semicolon-separated action list is readable and nearly every clause carries information. Slightly compressed, but no filler sentences.

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 7-action, 10-parameter dispatcher with no output schema, the description covers action selection and almost all parameter semantics, which is enough to call the tool correctly. The unexplained `limit` and the absence of any sibling-boundary note are the remaining gaps.

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?

With 0% schema description coverage across 10 parameters, the description carries the full burden and largely delivers: it maps parameters per action, explains `make`/`model` accept a name, alias, or id, defines `term` as a prefix filter, enumerates `scope` values with the default, and gives concrete `query` and `id` examples. It leaves `limit` unexplained, so it is strong but not complete.

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 verb and resource ('look up vehicles by year, make, model, submodel and engine') and enumerates the seven actions, which tells an agent exactly what the tool is for. It does not, however, distinguish itself from the sibling wenmar_vin, leaving the agent to infer the boundary between catalog lookup and VIN decoding.

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?

Each action is paired with the parameters it requires or accepts (e.g. engines needs make/model/year, optional submodel), which effectively guides action selection. What's missing is explicit routing guidance versus wenmar_vin and any statement of when a given action is not appropriate.

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