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

No annotations are supplied, so the description carries the full burden, and it does so unusually well: it discloses that the response includes per-register coverage counts (enabling the agent to report incompleteness honestly), scopes the result to 'what has been read so far' (a freshness caveat), and flags the systemic blind spot that many recalls are keyed by lot or best-before date rather than barcode. That is exactly the behavioural context an agent needs before relaying a negative result.

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 core action and return content are front-loaded in the first sentence, with the interpretive warnings following. The caveats are load-bearing rather than filler, though phrasing like 'so that finding nothing can be reported honestly' and the emphatic 'IMPORTANT' could be tightened without losing meaning.

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 single-parameter read tool with no annotations and no output schema, the description compensates well by describing both the recall list and the accompanying register-coverage figures. The main residual gap is that it does not characterise the notice payload itself (fields, dates, authority names), though the lot/best-before reference hints at that structure.

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 single 'code' parameter is already documented as digits-only EAN-13, UPC-A or GTIN. The description restates the same format list and adds only the real-world source context (printed on a bag, tin or pouch), so the baseline of 3 applies rather than a higher score.

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 (check/return) and a precisely scoped resource (every recall notice held against a given barcode across all covered registers), and names the accepted identifier formats (EAN, UPC, GTIN). An agent can immediately tell this is a single-barcode lookup and not a free-text or bulk search, distinguishing it from siblings like search_recalls or cross_border_recalls without opening any 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 clear conditions for use (you have the barcode printed on a bag, tin or pouch) and strong when-not guidance about interpreting an empty result ('no match does NOT mean the product is safe'). It also prescribes a follow-up step when a match returns (compare lot and best-before codes on the notice with those on the bag). It stops short of explicitly routing to a named alternative tool for non-barcode searches.

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