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

With no annotations provided, the description carries the transparency burden and it discloses the returned content (price, link, shipping/returns) and the affiliate-link fallback behavior. It does not cover error handling or empty results, but for a simple read operation the description is materially informative.

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?

Two sentences, front-loaded with the return value and followed by the key constraint. Every phrase adds information and there is no redundancy.

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 two-parameter tool with no output schema, the description gives the essential information: what is returned, how the product is identified, and the one-of constraint. It does not specify return formatting or behavior when no offers exist, but those are minor gaps for this complexity.

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 documents both parameters fully (100% coverage), so baseline is 3. The description adds meaningful semantics beyond the schema by requiring exactly one of slug or gtin, which is not represented in the schema's required 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 description names the operation ('Return'), the resource ('retailer offers'), the contained fields (price, link, shipping/returns info), and the lookup keys (slug or GTIN). This makes it easy to distinguish from get_product and search_catalog without opening schemas.

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 provides clear context: use this tool when you need a product's retailer offers and have either a slug or GTIN. It also states the exact-one-of constraint. It does not explicitly name alternatives or when-not-to-use cases, but the resource-focused context is sufficiently clear.

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