reserve_item

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

With no annotations, the description carries the full behavioral burden. It does disclose that the tool does not purchase, which is a key safety behavior. However, it omits other important behaviors such as side effects (inventory hold), reversibility, timeout, or idempotency implications. It provides only minimal transparency.

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 a single sentence that efficiently conveys the core action and its key exception (not purchasing). It is front-loaded with the verb and resource, and every word contributes to understanding. No fluff or redundancy.

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?

Despite having an output schema, the description is incomplete for a state-changing operation. It does not explain what happens on success or failure, how idempotency_key affects behavior, or what the response contains. Given the lack of annotations, an agent would be under-informed about the consequences of calling this tool.

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%, and the description does not explain either parameter. It mentions 'gift unit' but never ties it to item_id, and idempotency_key is entirely unexplained. The description adds zero value beyond the raw schema types, so the agent cannot infer parameter purpose or constraints.

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 states the action: 'Reserve one gift unit' and clarifies the critical nuance that it does not purchase it. This distinguishes it from a purchase action and gives a specific resource. While it doesn't explicitly reference sibling tools like release_reservation, the core purpose is unambiguous and actionable.

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 no guidance on when to use this tool versus alternatives such as release_reservation or other list/gift tools. It mentions 'after the buyer chooses' which implies a sequence, but there is no explicit when/when-not or mention of alternatives. An agent is left to infer context from the sibling list.

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