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

Annotations already establish this as a safe, read-only operation. The description adds two useful behavioral details: only active coupons are returned, and the content is in Brazilian Portuguese. It does not discuss pagination, rate limits, or authentication.

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 short sentences, both information-dense and front-loaded. There is no filler, and the second sentence adds a non-obvious output-language constraint.

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 simple read tool with full schema coverage, clear annotations, and an output schema, the description provides enough to call it correctly. The main gap is routing guidance among similar coupon-related siblings, but that is a minor omission.

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 store parameter is fully documented in the schema, including the slug source and example. The description adds no parameter-specific details beyond the schema, making the baseline score of 3 appropriate.

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 identifies the resource: active coupon codes for a specific store on Pechincha.ai. It does not explicitly differentiate itself from nearby siblings like list_deal_coupons or list_coupon_stores, though the phrase 'of a store' helps distinguish the scope.

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 the resource description and the prerequisite note that the store slug comes from list_stores. However, there is no explicit guidance on when to use this tool versus list_deal_coupons or list_coupon_stores, nor are exclusions stated.

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