Currency Convert

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

No annotations are provided, so the description must carry behavioral disclosure. It transparently reveals the data source ('open.er-api.com'), the fact that rates are live and USD-based, and the currency coverage scope. It does not discuss failure modes or rate limitations, but for a conversion tool this is meaningful transparency.

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 compact and front-loaded: purpose, use case, source/coverage, and code format each earn their place. There is no redundant wording or padding.

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 three-parameter conversion tool with an output schema, the description supplies all needed invocation context: what to pass, how codes should be formatted, which currencies are supported, and where rates come from. It is complete without needing to describe the return value.

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?

Schema description coverage is 0%, so the description must compensate. It does by specifying ISO 4217 codes with examples (CLP, BRL, USD), clarifying from_currency and to_currency. Amount is left as a plain number, which is already represented in the schema, so the added value is solid but not exhaustive.

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?

Begins with 'Convert an amount between any two currencies at the current rate,' which states a specific verb, resource, and scope. This clearly distinguishes it from sibling rate-lookup tools because it performs conversion rather than merely returning a rate.

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?

Provides clear practical context: 'Handy for pricing, invoicing and reporting across LatAm' and a concrete example (Brazilian price to Chilean pesos). It does not explicitly exclude alternatives or name sibling tools for rate-only lookups, so it stops short of full when/when-not guidance.

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