Check Currency Code

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

With no annotations, the description carries the disclosure burden. It does convey read-only validation behavior and the ISO 4217 membership criterion, but it does not state whether an invalid code returns false, raises an error, or how case sensitivity or code format is handled.

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 a single, front-loaded sentence with no filler or redundant information. Every word contributes to understanding the tool's core behavior.

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 is simple, has one parameter, and an output schema is present, so return values need not be described. The main gap is the lack of usage guidance relative to sibling list/check tools, but the essential invocation details are clear.

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 only defines code as a required string. The description adds meaningful semantics by specifying that the code must be a recognized ISO 4217 currency code. It still does not specify the expected format (e.g., uppercase 3-letter code), but for a single parameter it provides substantial context beyond the schema.

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 states a specific action ('Check') and resource ('ISO 4217 currency code'), and specifies the criterion ('recognized'). This distinguishes it from sibling tools like check_country_code and list_currency_codes without ambiguity.

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?

There is no guidance on when to use this tool versus alternatives such as list_currency_codes, which could be used to see all valid codes. No exclusions, prerequisites, or alternative recommendations are provided.

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