list_currencies

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

The only behavioral disclosure is the cost of $0.001 USDC via x402. With no annotations, the description fails to state whether the operation is read-only, what data it returns, or if authentication is required.

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 under-specified: the phrase 'list currencies' is redundant with the tool name, and the cost line is the only unique information. It lacks substance despite being short.

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 tool that lists currencies, there is no mention of the response format, whether it lists fiat/crypto, or how to invoke it with the generic params object. The absence of output schema and meaningful parameter info makes the description inadequate.

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 input schema contains a single generic 'params' object with no tool-specific properties. The description adds no parameter details, leaving users without any indication of what arguments to provide.

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 begins with 'list currencies', which is a direct restatement of the tool name. The added 'Data & Weather tool' provides a category label but does not clarify what currencies (fiat/crypto) or what output format to expect. This is tautological.

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?

No guidance is provided about when to use this tool versus the many sibling tools like convert_currency or currency_cross. There is no mention of prerequisites, alternatives, or typical use cases.

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