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

Beyond the readOnly/openWorld annotations, the description discloses critical behavior: the tool is paid via x402, costs $0.004 USDC on Base or Solana, and supports a free trial via X-Trial. It also states the result fields and the 20-result cap, though it omits any error/payment-failure behavior.

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, first stating the result type and fields, then the result limit, then the payment requirements. Every clause earns its place.

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?

It covers the key payment/auth model and result shape, which is important given no output schema. However, incomplete parameter documentation and absent alternative-selection guidance leave gaps for an agent trying to invoke it correctly.

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?

With 0% schema description coverage, the description should explain the four parameters. It only indirectly covers 'one query' and 'up to 20', and does not clarify the ambiguous q versus query fields or what gl means.

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 states the specific resource and result type: shopping product results with named fields, for one query, up to 20. This clearly differentiates it from generic search siblings, though it does not explicitly contrast against image_search or places_search.

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?

Usage is implied by 'shopping product results' and 'for one query', so an agent can infer product-search scenarios. However, it gives no explicit when-to-use or when-not-to-use guidance versus web_search, image_search, or other search siblings.

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