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

Even without annotations, the description discloses important behavior: it returns both active and exhausted redemptions, explains the per-row status values, notes that it is free, and states that proof of npub is required. It does not describe every detail such as dpop_token usage, but it is refreshingly transparent for a no-annotation tool.

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 compact and front-loaded with the core action, followed by useful behavioral details and status values. Every sentence earns its place, and there is no redundant 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?

With an output schema present and low parameter complexity, the description covers the main purpose, statuses, and cost/auth requirement. The main missing piece is dpop_token semantics and a clearer statement of when to choose this over the sibling list_coupons tool, so it is adequate but not fully complete.

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 must compensate. It adds some meaning to npub by associating it with patron proof, but it never explains the dpop_token parameter at all, including its relationship to proof of npub or why it has a default empty string. This is a significant gap for a two-parameter tool.

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 and resource: listing the coupons a patron has redeemed on an operator. The scope is explicitly narrowed with 'this patron' and 'this operator,' and the return statuses are enumerated, making it distinguishable from siblings like roastify_list_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?

Provides clear context for when the tool is appropriate: to list a patron's redeemed coupons on the current operator. It does not explicitly name alternatives or exclusion conditions, but the 'my coupons' scope is clear enough to guide selection.

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