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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description's 'Look up/조회' aligns with that read-only behavior. The description adds a per-call cost note ('[호출당 3포인트]') and downstream use cases, which is useful context. It does not disclose output shape or edge-case behavior, but for a safe read-only lookup the annotations carry most of the burden.

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 three short sentences, with the primary lookup action and scope front-loaded. The Korean sentence repeats the English statement, which is mildly redundant, but the overall size is compact and the extra cost/use-case information is earned.

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 simple two-parameter read-only holiday lookup, the description plus schema covers what an agent needs to call it correctly. There is no output schema, so the description could have described the returned holiday information, but this is a minor gap for a straightforward query tool. The cost note and read-only annotations round out the operational context.

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%: both year and month are documented with type, range, and example values. The description only restates 'given year and month' and does not need to add further parameter detail. The baseline of 3 applies because the schema fully handles parameter semantics.

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 ('Look up') with a clearly bounded resource: Korean public holidays for a given year and month. The bilingual text and the stated use cases ('영업일 계산, 일정 관리') make the tool's role unambiguous. It is easily distinguished from the sibling tools, none of which target holiday data.

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 usage context by stating the tool is for business-day calculations and schedule management. It does not explicitly name alternatives or when-not-to-use conditions, but the sibling list contains no competing holiday tool, so the guidance is sufficient.

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