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

Beyond the readOnlyHint and destructiveHint annotations, the description adds substantial behavioral detail: sold-out offers are included to keep store_count consistent with search_beauty_prices, in_stock_store_count counts shippable offers, shipping semantics are defined, cheapest_store_incl_shipping vs is_cheapest are distinguished, and below_min_order is explained. This gives an agent reliable expectations about edge cases and return semantics.

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 its core purpose and usage, then organized into clear paragraphs and an Args section. It is longer than strictly necessary because an output schema exists, but the detailed output semantics are behaviorally useful and not filler. Slight trimming could be possible if the schema documents the field names, but overall structure and clarity are strong.

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 its complexity, the description covers when to use the tool, where to obtain the required parameter, supported markets, how to discover additional markets, and the exact semantics of in-stock, shipping, cheapest-store, and minimum-order behavior. No critical piece of information an agent would need to select and call this tool correctly appears to be 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 by defining product_slug as a value originating from search_beauty_prices and by listing valid country codes with a pointer to get_service_info for the current market list. This adds real semantic meaning beyond the bare schema properties. The only minor omission is not stating the 'se' default, but the schema already exposes that.

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 'Compare one product's price across all stores that sell it', which clearly identifies the verb, resource, and scope. It also separates this tool from search_beauty_prices by instructing that product_slug must come from that tool, and the focus on a single product's cross-store comparison distinguishes it from siblings like get_price_history and find_deals.

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 where to buy a specific product or wants to see every store's price for it'. It also gives a clear prerequisite by telling the agent to get product_slug from search_beauty_prices. However, it does not explicitly name exclusions or alternatives such as find_deals or get_price_history, so it stops just short of full when-not-to-use guidance.

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