list_currency_codes

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

With no annotations, the description carries the transparency burden. It clearly indicates a read-only listing operation and specifies the source code list, which is helpful. However, it does not mention whether the list reflects the latest CEF EN 16931 version, whether codes include names or descriptive metadata, or whether any filtering or pagination applies.

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?

A single, concise sentence that front-loads the action and resource. There is no redundant wording or filler, and every part of the description adds meaning.

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 parameterless listing tool with an output schema available, the description states the domain (ISO 4217), the source (CEF EN 16931), and the operation (list). Nothing essential is missing for an agent to decide to invoke this tool.

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 has zero parameters, so the description does not need to explain parameter behavior. The description accurately conveys that the tool simply lists codes with no input required, which is sufficient given the empty 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 states a specific verb ('List') and a clear resource ('ISO 4217 currency codes from the CEF EN 16931 code list'). This distinguishes it from sibling tools like check_currency_code, which validates a single code, and list_country_codes, which lists a different code set.

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 implies a listing use case but does not explicitly state when to use this tool versus check_currency_code or other list tools. An agent can infer the appropriate use from the phrasing, but there is no direct guidance or exclusion of alternatives.

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