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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description still adds real behavioral value by disclosing result content (active coupon count, commission rate with the conditional 'when the network publishes it'), which signals fields may be absent for some stores. No output schema exists, so surfacing these traits is genuinely useful.

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 begins with the action and resource before enumerating result fields. It is somewhat dense with a long trailing clause list, but every clause earns its place by describing what is returned where no output schema exists.

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 no output schema, describing the returned fields is essential and the description does it well, including conditional availability of commission data. What is missing is result ordering/pagination semantics and routing guidance versus get_store_link, which keeps it out of the top band.

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 query, limit, countries, and cashbackOnly are all documented in the schema. The description adds no parameter-level meaning beyond that, so the baseline 3 applies.

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?

States a specific verb+resource ('Find stores (merchants) by name or domain') and clarifies the search key, which cleanly distinguishes it from the coupon and product search siblings. It does not name or contrast with get_store_link, even though it advertises returning 'a tracked link to the store,' leaving mild overlap unaddressed.

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?

There is no explicit when-to-use guidance, no prerequisites, and no mention of alternatives. Worse, the promise of a 'tracked link' overlaps with the sibling get_store_link without explaining when the agent should prefer one over the other.

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