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

Annotations already cover readOnlyHint=true, idempotentHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is complete. The description adds that it returns a compact field set, which hints at behavior but doesn't disclose pagination, rate limits, or query semantics beyond what the schema/annotations provide.

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?

A single, front-loaded sentence that lists the return fields efficiently with zero waste. Appropriate for the compact nature of the tool.

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?

With an output schema present, the description needn't explain return values fully, and annotations cover safety. However, with 0% schema coverage and no parameter documentation, the description is missing key invocation guidance (what query does, what merchant/limit affect). It's adequate but incomplete.

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 0%, so the description should compensate but doesn't mention any of the three parameters (query, limit, merchant). The baseline is 3 when schema coverage is high, but here it's 0% and the description adds no parameter meaning, leaving a gap.

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 resource (search results) and specific fields returned (name, brand, price, availability, buy URL, markdown page URL). It names the sibling search_catalog and conveys a key differentiator (smaller answer). However, it doesn't fully explain the search semantics beyond being 'smaller' than search_catalog.

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 by comparing to search_catalog ('Smaller answer than search_catalog'), suggesting it's for compact results, but doesn't explicitly state when to use it versus search_catalog or lookup_catalog. No clear when-not-to-use guidance.

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