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

Annotations already cover readOnly and non-destructive behavior, so the description adds useful extra context: slugs are identical across markets, display names are localized, and the 'Controversial' category maps to exclude_controversial=True. This goes beyond the structured fields 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 compact and front-loaded with the essential purpose. The 'Args' section is clearly separated, and every sentence adds either usage guidance or behavioral context without fluff.

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 simple listing tool with an output schema, this description is complete. It covers purpose, usage triggers, localization behavior, the controversial-category link, and parameter semantics. Nothing critical is missing.

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%, but the description fully compensates for the country parameter by explaining it is the market for localized display names and listing valid values: 'se', 'no', 'dk', 'fi'. It also notes that get_service_info returns the current market list, which is valuable for future-proofing.

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 opens with a specific verb and resource: 'List the 67 ingredient groups accepted by key_ingredient and exclude_ingredient in search_beauty_prices.' This clearly identifies what the tool does and distinguishes it from the sibling search/price tools.

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: 'Use when you need a valid ingredient slug, or to show the user which ingredients can be filtered on.' It provides clear context but does not explicitly name alternatives or exclusions, so it stops short of a 5.

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