유치원 정원·현원·여석 추정 조회(유치원알리미 공시 정보)

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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so the safety profile is covered; the description adds genuinely new behavior — an external OpenAPI dependency requiring KINDERGARTEN_API_KEY authentication, real-time fetching, and the epistemic caveat that 여석 is an estimate rather than live data. It does not mention rate limits or failure modes, which keeps it below a 5.

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?

Two sentences, front-loaded with the data source and returned fields, then the estimate caveat and auth requirement. It is dense but each clause carries information; the returned-field enumeration is long, though justified given there is no output schema.

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?

With no output schema, the description compensates by enumerating the returned fields, and it also covers the estimate caveat, the non-enrollment scope boundary and the required API key. An agent has everything needed to decide to call it and to interpret the results correctly.

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%, and the schema already explains the age sorting behavior, the 1–30 limit with default 10, the 시군구-level region format and the partial-match establish filter. The description adds no syntax or semantics beyond that, so the baseline 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?

The description names a specific verb and resource: real-time lookup of 유치원알리미 general-status disclosure data at 시군구 level, returning per-kindergarten 설립유형·주소·전화·공시 차수 and age 3/4/5 정원·현원·학급수 plus estimated vacancies. That is concrete enough to separate it from sibling find_daycare and from the clinic/benefit finders without opening the schema.

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?

It makes the use case clear (checking capacity/vacancy estimates by district) and adds exclusions — vacancies are disclosure-based estimates, so real-time recruitment/waiting status and admissions must be confirmed with the kindergarten, and the tool does not act as an enrollment agent. It stops short of naming an alternative tool for those needs, so it is clear context rather than a full when/when-not routing rule.

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