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

The description adds substantial operational context beyond the annotations: paid per call, up to 10 rows returned, monthly file freshness, omitted inconsequential recalls, omitted remedy text and VINs, and no charge when there are no matches or stale data. These are meaningful behavioral traits not covered by the read-only/idempotent 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?

The description is dense and front-loaded, beginning with 'PAID, per call' and then covering scope, input guidance, return limits, exclusions, and billing exceptions. Every sentence contributes operational information without repetition.

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 paid search tool with no output schema, the description covers cost, result limits, data freshness, exclusions, and billing exceptions well. It only partially describes the returned row structure beyond saying each row includes dates, so there is a small gap for output expectations.

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 description coverage is 100%, so the per-parameter definitions already carry most semantics. The description still adds a useful cross-parameter constraint: the caller should provide a make, recall number, or keyword, which is not obvious from the schema alone since zero parameters are marked required.

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 and resource: search Transport Canada's Vehicle Recalls Database by make, model, model year, recall number, and keyword. It clearly distinguishes this tool from sibling recall searches such as search_health_canada_recalls and search_us_fda_recalls by naming the Canadian vehicle domain.

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 instruction 'give a make, a recall number or a keyword' establishes a minimum identifying input, and 'PAID, per call' plus the no-charge conditions give useful context for when to invoke it. However, it does not explicitly compare this tool with sibling recall or lookup tools, so the alternatives guidance is incomplete.

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