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

With no annotations provided, the description carries the full behavioral disclosure burden. It does this excellently by stating the operation is cosmetic, non-destructive at the operator level, re-redeemable by the patron, free, and requiring proof of npub. This is materially richer than the bare schema and gives the agent a clear model of side effects.

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?

Three short sentences deliver the core action, the critical caveat, and the cost/auth condition. There is no wasted phrasing, and the most decision-relevant fact ('Cosmetic only') appears immediately after the action. Ideal front-loading for an agent deciding whether to call this tool.

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 small mutation tool with an output schema, the description is nearly complete: it explains purpose, behavioral caveats, pricing, and an auth requirement. The remaining gap is lack of explicit routing relative to delete_coupon and no guidance on dpop_token, but these are minor given the tool's simplicity and available schema.

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 does clarify the role of npub ('this patron') and coupon_id ('a coupon'), but it does not explain dpop_token at all and gives no format or derivation hints. The compensation is partial: core parameters are inferable, but the optional parameter remains opaque.

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 uses a specific verb and resource: 'Remove a coupon from this patron's redemption list.' It clearly distinguishes this from a permanent deletion by stating 'Cosmetic only — the coupon itself still exists at the operator.' This makes the tool's unique role immediately understandable, especially against the sibling delete_coupon.

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 gives clear context for when to use this tool: when you only want to remove a coupon from a patron's visible list without destroying it. It implies the alternative of a real delete by saying the coupon still exists and can be re-redeemed, but it does not explicitly name delete_coupon or state 'when not to use.'

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