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

Beyond the readOnly/idempotent/non-destructive annotations, the description discloses provenance and accuracy limits: the ewg fields are Folsn's own estimates and not official EWG ratings, and no skin-safety claim is made. That is exactly the kind of caveat an agent needs before relaying results. It does not say what happens when neither optional parameter is supplied or when values conflict, leaving one behavioral gap.

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, scope limitation and estimate disclaimer, is front-loaded and free of filler. Length is roughly doubled by the Korean/English mirroring, which is a deliberate localization pattern rather than padding, but it does make the definition longer than strictly necessary for one language.

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 an output schema present, the description correctly avoids explaining return values, and the two parameters are fully documented in the schema. What remains unsaid is the interaction between the two optional inputs and behavior when both are omitted, which matters for a tool where every parameter is optional.

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 both parameters carry descriptions and examples, so the schema already does the semantic work. The description adds nothing about how ingredients_text and product_name_or_id relate or which takes precedence, 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?

The description gives a specific verb and resource in both languages ("사용자가 직접 입력한 성분명을 분류합니다" / "Classify user-supplied ingredient names"), and narrows scope with "no product-specific ingredient or skin-safety claim," which implicitly separates it from the catalog/product siblings. It never states what the classification produces (categories, grades, flags), so the agent must infer from the ewg* field names that grading is the output.

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?

"user-supplied" implies the tool is for ingredient text the user pastes rather than a product lookup, which is a usable, if implicit, routing signal against get_beauty_product_detail and search_beauty_products. No sibling is named, and there is no explicit when-not guidance, so the agent must infer the boundary itself.

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