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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorld=false, so the safety profile is covered. The description adds real behavioral content the annotations do not: a hard cap of 20 matches and the exact returned fields (barcode, lowest/median/highest shelf price in ILS across chains, and a link). It does not discuss rate limits, chain coverage, or empty-result behavior.

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, zero filler. The core capability and scope come first, the return payload second, and the routing hint last — a clean front-loaded structure.

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?

With no output schema, the description carries the return-value burden and does so adequately (fields, price basis in ILS, link, 20-item cap). Annotations cover the safety profile. Minor gaps remain: it never states which chains are covered or what an empty result looks like, so it is strong but not exhaustive.

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 50%: the query parameter is well documented in the schema with a Hebrew example, but limit is not described at all. The description's "up to 20 matches" partially implies the limit ceiling, but it adds nothing about query semantics beyond what the schema already says. Baseline 3 is right when the schema does most of the work and the description only loosely echoes it.

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 (search products) plus the domain (Israeli supermarket products) and the two accepted lookup keys (Hebrew name or barcode). It also distinguishes itself from the sibling get_product_prices by naming that tool and its role, so an agent can route without opening either 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?

Explicitly routes the agent: use this to find a product, then pass the barcode to get_product_prices for per-chain prices. That is a concrete alternative with a selecting condition, though it gives no explicit "do not use this when" case (e.g. for deals or basket comparisons, which siblings cover).

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