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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true. The description adds the data range (1966 to present) but does not disclose any other behavioral traits such as authentication requirements, rate limits, or pagination behavior. With annotations covering safety, the description contributes minimal additional behavioral insight.

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 consists of two concise sentences. The first sentence clearly states the purpose and return fields, and the second adds context about the date range and target users. Every sentence is necessary and front-loaded, with no wasted words.

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?

Given that the tool has a full input schema, annotations covering safety, and an output schema (context signal), the description is nearly complete. It explains what the tool does, what it returns, and the data coverage. However, it lacks details on pagination or response size limits, but this is not critical for basic tool selection.

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 has 100% description coverage for all 3 parameters (make, model, model_year) with clear and detailed descriptions. The tool description does not add any extra meaning beyond what the schema already provides, so a baseline score of 3 is appropriate.

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 'Search' and identifies the resource 'NHTSA vehicle recalls'. It lists the return fields (campaign number, manufacturer, subject, etc.) and the date range (1966 to present). This clearly distinguishes it from sibling tools like vehicle.safety.complaints or vehicle.safety.ratings, as it focuses solely on recalls.

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 states it is 'Essential for automotive safety, insurance, and fleet management agents', which provides some context for use. However, it does not explicitly state when to use this tool over alternatives, nor does it provide exclusions or conditions for use. There is no mention of when not to use it, leaving some ambiguity for the agent.

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