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

With no annotations, the description carries the behavioral burden. It communicates that this is a read-only list operation and additionally explains the optional filtering behavior ('주면 ... 반환'). It could mention output format or full-list behavior when no parameter is given, but it is still transparent for a simple lookup tool.

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 short, front-loaded sentences with no filler. The description immediately states what the tool provides and how it should be used, which is ideal for agent consumption.

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 single-optional-parameter code-list tool with no output schema and simple siblings, the description is complete enough. It states the resource, its intended downstream use, and the parameter's conditional behavior. An agent can confidently decide to call this tool to obtain valid areaCode values.

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 covers the parameter meaning well (100% coverage), so baseline is 3. The description adds value by explaining that the returned codes are intended for use as the areaCode argument in other tourism tools, which helps an agent understand why and how to use the parameter.

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 identifies the resource (한국관광공사 지역코드 목록, Korea Tourism Organization area code list) and its purpose: supplying the areaCode argument to other tourism tools. This distinguishes it from sibling tools like korea_bus_cities and korea_weather_normals.

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 explicitly states this tool's output is meant for the areaCode parameter of other tourism tools, giving clear usage context. It does not name specific alternatives or exclusion conditions, but for a simple code-list tool this is sufficient context.

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