Look up car brands and models

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavioral context beyond that: this is the canonical-name resolution step, and kn_price_list expects different variant names than kn_cars. It stops short of describing the returned structure (e.g. whether brand/model are nested), which keeps it off a 5 given there is no output schema.

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?

Three short sentences, each carrying distinct information: purpose, ordering/prerequisite, and the cross-tool naming caveat. The most decision-relevant instruction ('Use first') is front-loaded in the second sentence with zero filler.

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 one-parameter read-only lookup with no output schema, the description covers purpose, sequencing, and the downstream handoff adequately. The only gap is that it does not sketch the shape of the result (brand/model pairs), which an agent must infer, though the tool's purpose makes that low-risk.

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% and the single query parameter is fully documented there, including substring matching and the empty-string-lists-all behavior, so the baseline of 3 applies. The description reinforces the Persian/English dual-name intent but adds no syntax or matching details beyond the schema.

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?

States a specific verb and resource ('Look up ... car brands and models'), plus the key attribute that it returns both Persian and English names. It is clearly distinguishable from kn_cars (which consumes the results) and kn_price_list (which uses different variant names), so an agent can tell the tools apart without opening a 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?

Gives an explicit ordering rule ('Use first when you only have a Persian name or are unsure of the spelling'), names the downstream consumer ('Pass the English brand and model values to kn_cars'), and flags the exception ('Zero-km price lists (kn_price_list) use their own English variant names'). When-to-use, what-to-do-next, and an exclusion are all present.

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