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

The annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds useful behavioral context beyond that: results are sorted newest-first, only US NHTSA recalls/equipment are included, and each item includes risk and remedy information. There is 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 sentence packs in the resource, scope, source, ordering, and output contents. There is no filler, and the most important information is front-loaded. The description earns its place and nothing more is needed.

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 simple read-only list tool with one optional parameter and no output schema, the description is sufficient: it explains the domain, ordering, and key output fields. It does not enumerate all possible response fields, but the stated 'risk and remedy' coverage is likely adequate for an agent to interpret results.

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 only parameter, 'limit', is fully documented in the input schema with type, default, min, max, and a description. The tool description adds no additional parameter semantics, but with 100% schema coverage, the baseline 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 states a specific action ('List'), a precise resource ('newest US vehicle and equipment recalls from NHTSA'), and the output characteristics ('newest first, with risk and remedy'). It clearly distinguishes this list tool from the singular lookup tool 'vehicle_recall' and from unrelated siblings like 'latest_kev'.

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 phrasing clearly signals when to use this tool: when the agent needs a list of the most recent NHTSA recalls rather than a specific recall lookup. It does not explicitly name alternatives or exclusions, but the context is clear enough for selection among the siblings.

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