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

With no annotations provided, the description carries the behavioral burden. It discloses that the tool checks coverage and disambiguation but does not describe output format, matching behavior, or edge cases. It adds some context beyond the tool name, so it is not purely tautological.

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?

Two sentences with no filler. The primary action and scope come first, and the usage guidance is packaged concisely in the second sentence. Every word earns its place.

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 single-parameter search tool with a sibling workflow, the description gives enough context to understand purpose and when to invoke it. It could mention what the response contains, but the low complexity and clear role in the workflow make the description largely complete.

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 coverage is 100% and the only parameter 'q' is documented as a free-text query with an example. The description says 'free text' but adds no meaning beyond the schema's own description, so the 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 names a specific action ('Search'), a specific resource ('covered vehicles'), and a scope ('530 UK model generations'). It also explicitly positions itself relative to mot_reliability, making the tool's purpose unambiguous and differentiating it from its sibling.

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 clear usage context: use this tool to check coverage or disambiguate before calling mot_reliability. It does not list exclusions or when-not-to-use scenarios, but the sibling is named and the workflow is clear.

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