Estimate a car's market value

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

The annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. Beyond that, the description discloses the return shape (average, lower and upper price in Toman) and the important failure path (if no estimate exists, ask the user for the value), which annotations cannot express. It does not discuss estimate recency or accuracy, hence not a 5.

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?

Roughly four short sentences, front-loaded with the purpose and then sequenced prerequisite → downstream use → return/fallback. Every sentence carries actionable information, though the hard line breaks read as fragmented notes rather than prose.

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?

There is no output schema, and the description compensates by naming the returned fields and their currency, plus the no-estimate fallback. For a read-only, three-parameter estimator with full annotation coverage, nothing an agent needs in order to call it and interpret the result is missing.

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%, including the note that vehicle_id comes from ins_vehicles, so the schema already carries the parameter meaning and the description's provenance remark is largely redundant. It adds no detail on the Jalali year range or what zero_km changes about the estimate, 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?

"Estimate a car's market value the way Azki does before pricing body insurance" gives a specific verb (estimate) and resource (car market value), plus the downstream purpose. The opening line plus "Azki only" separates it from generic valuation or sibling quote tools without needing the schema.

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?

It states a hard prerequisite ("Call ins_vehicles first for the model id"), an explicit scope exclusion ("Azki only"), and the exact downstream consumers with their parameter names (car_value in ins_quote_car_body, vehicle_price in ins_azki_body_options). An agent knows both when to call it and what to do with the result.

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