horizon_redeem_gift_codeRedeem a gift code on horizOn for a user by supplying the code and user ID. This tool applies promotional codes to user accounts.
Redeems a gift code on horizOn for the given user.
| Name | Required | Description | Default |
|---|---|---|---|
| code | Yes | Gift code to redeem (max 50 characters) | |
| userId | Yes | User ID (UUID) |
Changes observed during successful MCP inspections.
v1.5.4Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden and delivers almost nothing: it doesn't state whether redeeming consumes the code, whether it is irreversible, what auth is required, what errors occur (invalid/expired/already-redeemed), or what the response contains. For a mutating redemption operation this is a significant gap.
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 single sentence is front-loaded and free of filler, which is good, but it is so thin that it functions more as under-specification than as conciseness.
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?
No annotations, no output schema, and a mutating tool with a closely related sibling (validate_gift_code) left unmentioned. Given the complexity of redemption flows, the description is not complete enough for an agent to invoke it confidently.
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%, with both 'code' (max 50 chars) and 'userId' (UUID) fully documented in the schema. The description adds no parameter syntax or format detail beyond that, so the baseline of 3 applies.
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 (Redeems) and resource (gift code) with the target user, so the core action is unambiguous. However, it does not distinguish itself from the sibling horizon_validate_gift_code, which an agent could easily confuse with this tool.
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?
There is no when-to-use guidance, no prerequisites, and no mention of alternatives. The sibling horizon_validate_gift_code exists and presumably should be used to check a code before redeeming, but the description never says so.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.