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

The description adds behavioral context beyond the annotations by stating that inventory is checked in real-time, which is not captured by readOnlyHint or idempotentHint. It also implies a single-stay scope. There is no contradiction with the annotations.

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 two concise sentences, front-loaded with the main action in the first sentence and a critical caveat in the second. No unnecessary words or repetition.

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?

The tool has an output schema, so return format is covered elsewhere. The description provides the key differentiator (real-time inventory recheck) and indicates a single-stay query. It could mention more about when to call it, but given the schema and annotations, it is adequately complete for correct selection and invocation.

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?

The schema already documents most parameters (stay_id, checkin, checkout) with descriptions, leaving only 'guests' undocumented. The tool description does not elaborate on parameter usage or how they affect inventory queries, so it adds little beyond the schema. With 75% schema coverage, a baseline score of 3 is appropriate.

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 explicitly states the tool queries detailed information and inventory for one accommodation ('숙소 하나의 상세 정보와 재고를 조회한다'), using a specific verb and resource. It also distinguishes itself from siblings by noting that real-time inventory rechecking is only done here ('재고 실시간 재확인은 여기서만 한다'), which differentiates it from stay_search and stay_booking_link.

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 phrase '재고 실시간 재확인은 여기서만 한다' provides explicit guidance to use this tool for real-time inventory verification, indicating a clear use case. It doesn't explicitly mention alternatives for other purposes, but the unique purpose is clearly implied. Sibling tool names provide additional context.

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