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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds meaningful behavioral context: devices and accessories lack INCI lists, certifications are third-party while brand_claims_unverified are the brand's own statements, and the latter should be presented as claims. This goes beyond the annotations without contradicting them.

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 description is front-loaded with purpose and usage, then provides field-level semantics and product-type caveats. Every section earns its place: the INCI caveat, certification vs. brand claim distinction, slug source, and country list all add necessary information without filler.

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?

Given the tool's complexity, two parameters, output schema, and sibling context, the description is complete. It covers when to use the tool, how to obtain the required parameter, acceptable market values, and how to interpret certifications versus brand claims. It even handles the edge case of devices and accessories without INCI lists.

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 0%, so the description carries the full burden for parameter meaning. It defines product_slug as the value from search_beauty_prices and enumerates all current country codes with the note that get_service_info returns the updated list. This fully compensates for the bare string-type schema fields.

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 opening sentence names a specific action ('Return full details') and resource ('one product') and enumerates the returned contents: INCI ingredient list, key ingredients, description, images, and brand-level certifications and claims. This clearly distinguishes it from sibling tools that search, compare, or list prices.

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 description explicitly states when to use the tool: when the user asks what a product contains, whether it includes or avoids an ingredient, or whether a brand's vegan/cruelty-free/organic status is certified. It also tells the agent to get product_slug from search_beauty_prices. However, it does not explicitly contrast with sibling list_key_ingredients or give negative usage cases, so it stops short of a full 5.

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