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

Annotations already cover read-only and open-world safety, but the description adds crucial behavioral details: the data source (products.json), that no key is required, failure mode (404 for blocked stores), and the pricing model ($0.002 USDC per successful call, paid via x402 on Base/Solana/Arc, failed calls not charged). This goes well 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 three sentences: first sentence front-loads the data returned and its source, second notes the failure condition, third states pricing. Every sentence is informative and there is no redundancy or filler.

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 that an output schema exists and annotations cover safety, the description provides sufficient context: source, fields, failure mode, and pricing. It could mention rate limits or pagination behavior, but these are minor gaps for a simple retrieval tool.

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 100%, so the schema fully documents both parameters (domain and limit). The description does not add any meaning beyond what the schema provides, which is the baseline for high coverage.

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 clearly states it retrieves public product metadata from a Shopify store's products.json feed and enumerates the exact fields returned. It is distinguishable from all siblings, which are unrelated search tools. A stronger verb like 'Retrieves' could make it a 5, but the purpose is 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 implies usage for Shopify store product data and notes that only stores exposing products.json work (others return 404). However, it does not explicitly say when to use this tool versus alternatives or provide explicit when-not-to-use guidance beyond the 404 caveat.

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