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

Annotations already establish the read-only, open-world nature, so the description needs only add extra behavioral context. It adds that the tool is free and that it returns the complete bank list for use as an input reference. It doesn't describe response structure or update behavior, but these are minor for a zero-argument list 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?

The main purpose is front-loaded and clear, and the use case is useful. However, the same information is repeated in English and Korean, and '무료입니다. [무료]' duplicates the free notice, adding minor noise.

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 zero-parameter tool, the description is functionally complete: an agent knows what it returns, why it exists, and that it costs nothing. Without an output schema, a sample return shape would be a nice addition, but the stated purpose 'bank codes and names' adequately implies the output.

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 tool takes no parameters, so there are no parameter semantics for the description to illuminate. The baseline for zero-parameter tools is 4, and the description correctly focuses on the output data instead.

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 opens with a concrete verb and resource: 'List Korean bank codes and names,' and further clarifies it returns the full list ('전체 목록을 반환합니다'). This clearly distinguishes bank_code from the many sibling tools and states exactly what data is returned.

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 explicitly states the intended use case: finding the bank_code input value for transfer_1won and account_realname. It stops short of giving exclusions or comparing to alternatives, but no sibling provides a comparable bank-code lookup, so this is sufficient direction.

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