DNS-Shop Product Card

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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds specific error behaviors (BadRequestError, TransportDownError, ParserDriftError) and a condition for parser drift, providing context beyond the 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 well-structured with clear sections and no wasted words. The Return Format section may duplicate what the output schema already provides, but it is brief and doesn't bloat the description.

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 scraping tool with potential failures, the description covers purpose, input requirements, return format, and all relevant error modes. Since an output schema exists, the return format section is a bonus rather than a gap.

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 product_url with an example and full coverage. The description adds semantic value by explaining that a BadRequestError occurs when the URL carries no product id, reinforcing the expected URL structure.

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 'Fetch one DNS-Shop product card', which clearly states a specific verb and resource. This distinguishes it from sibling tools like dns_search (search) and other marketplace card tools, making the purpose unambiguous.

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 clearly implies this tool is used when you need a single product card by URL, and the input requirement for a product URL provides context. However, it does not explicitly mention alternatives or when-not-to-use, so it falls 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.