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

Annotations already cover read-only, idempotent, open-world and non-destructive behavior, so the bar is lower. The description still adds real value beyond them: it discloses that up to five matches are returned, that each carries a verdict, that a 'say' line exists for the best match, and that brand statements can override an unnamed ingredient source.

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 substantive content (search scope, result shape, brand_statement rule) is useful and reasonably front-loaded, but the opening two sentences largely restate the title and name, spending words without adding information. Middle-heavy rather than tight.

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: match count, verdict field, 'say' line, and brand_statement. Combined with annotations covering safety, an agent has enough to invoke correctly, though sibling routing remains thin.

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 both q and country are already documented in the schema, including the barcode example and country slug semantics. The description repeats the 'Haribo Starmix' example but adds nothing about the country parameter or the Amazon-store side effect, so it sits at the baseline.

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: searches Open Food Facts by name or brand and returns products with a verdict. The name/brand vs barcode framing implicitly separates it from halalornot_check_product_by_barcode, though it never names a sibling. An agent can identify what it does but must infer differentiation.

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?

Implied usage via 'Find products by name and check them' and the name/brand example, but there is no explicit when-to-use or when-not guidance, and the obvious alternative (halalornot_check_product_by_barcode) is not mentioned. Context is present but leaves routing to inference.

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