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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful content detail (results include store, domain, and cash-back rate), but says nothing about pagination, result volume, or region coverage for an open-world listing.

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?

Two tight clauses with no filler, and the scope/returned-fields information is front-loaded before the usage guidance. Slightly dense with parenthetical enumerations, but everything 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?

For a no-parameter, read-only listing tool with an output schema that already documents return values, the description covers purpose, scope, returned fields, and when to prefer it. Nothing an agent needs to invoke it correctly is missing.

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 tool takes zero parameters, so the baseline is 4. There is nothing for the description to compensate for, and it correctly does not fabricate parameter semantics.

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 (List) and resource (RetailMeNot's current cash-back offers), specifies scope (featured, top, and all), and describes the returned fields (store, domain, cash-back rate). It also differentiates from the sibling store/coupon tools by contrasting 'across stores' with 'one store's coupons'.

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?

Gives an explicit condition ('when you want the highest cash-back rates across stores') and an exclusion ('rather than one store's coupons'). It stops short of naming the exact sibling tool to use instead, but the routing intent is clear.

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