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

Annotations already declare readOnly, idempotent, closed-world, and non-destructive, so safety is covered. The description usefully reveals that matching is synonym/INCI-aware (e.g. 'Prunus amygdalus dulcis oil' → tree nuts), but it doesn't say what happens for an unrecognized ingredient or how many allergen groups can come back.

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?

A single front-loaded sentence with the purpose stated first and examples used as compact illustration. No wasted words.

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 does convey the return value ('which allergens, if any') including the empty case via 'if any'. The only gap is behavior on unrecognized or ambiguous ingredient names.

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 parameter is already documented as 'One ingredient name as printed on a label.' The examples reinforce the expected input format but add little beyond the schema, so the baseline of 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?

States a specific verb ('Tell which allergens') and resource ('an ingredient name'), with three concrete examples that make the ingredient→allergen-group mapping unmistakable. It doesn't explicitly distinguish itself from check_product_allergens, but the singular-ingredient scope is clear from the phrasing and examples.

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?

The examples imply usage (label-printed ingredient names, INCI-style names), but there is no explicit when-to-use or when-to-prefer-a-sibling guidance, e.g. no statement that this is the ingredient-level lookup versus the product-level check_product_allergens.

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