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

The description discloses that the tool may return `addons` — optional items with `required` flag and `price_modifier`, which goes beyond the annotations (readOnlyHint, destructiveHint) that only indicate read-only and non-destructive behavior. No contradictions with annotations.

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 a single paragraph, fairly concise, but combines functional purpose with usage instructions. While efficient, it could be slightly more structured (e.g., separate usage guidelines). Still, no unnecessary verbosity.

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 complexity of the tool (returning addons with important implications for cart flow) and the presence of an output schema (so return values don't need elaboration), the description sufficiently covers all aspects needed for correct usage. It tells the agent exactly what to do with addons, ensuring completeness.

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?

The schema already has 100% coverage with descriptions for both parameters (site_id and product_id). The description does not add additional parameter-specific semantics; it only mentions them in the context of the product retrieval but no extra details like format or constraints. Baseline score of 3 is appropriate.

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 uses specific verb 'Retrieve detailed information about a specific product' and lists key resources (variants, pricing, images, availability, addons). It clearly distinguishes from sibling tools like search_products (search) and compare_products (comparison) by focusing on a single product's details.

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?

Provides explicit when-to-use guidance: it tells the agent to present addons to the buyer, collect required addons before calling add_to_cart, and show price modifiers. It also instructs to keep reply brief because the card already shows product details. This directly addresses tool selection and downstream usage.

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