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

With no annotations provided, the description fully carries the behavioral disclosure burden. It reveals validation of the validity window and total cap, recording of a per-patron redemption row, automatic discount application until uses_per_patron is exhausted, the free cost model, the npub proof requirement, and idempotency. This is comprehensive and exceeds minimal expectations.

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 dense and well-structured: it opens with the core action, then layers side effects, cost, prerequisites, and idempotency in a natural order. Every sentence contributes meaningful information with no 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?

For a redemption tool with three parameters and an output schema, the description is remarkably complete. It covers purpose, preconditions, side effects, cost, and repeat-call behavior. The missing dpop_token detail falls under parameter semantics, and explicit alternative routing is not essential given the clarity of the purpose.

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 usefully defines 'code' as the shared coupon name and explains the proof requirement for npub. However, the optional dpop_token parameter is never mentioned, leaving one of three parameters semantically undocumented.

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 opening sentence 'Claim a coupon by its name (the code the operator shared)' clearly states the action, object, and input terminology. It distinguishes redemption from coupon lifecycle tools like mint, update, delete, and list coupons, leaving no ambiguity about the tool's purpose.

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 provides clear operational context: the tool is free, requires proof of npub, is idempotent, and produces side effects on future paid calls. It does not explicitly name alternatives or state when not to use it, but the context is strong enough for an agent to select it appropriately.

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