Convert a currency amount between two currencies using Open Exchange Rates; provide the source currency, target currency, and amount to get the converted value.
Convert a currency amount using Open Exchange Rates.
| Name | Required | Description | Default |
|---|---|---|---|
| to | Yes | ||
| from | Yes | ||
| amount | Yes | ||
| api_key | No |
Changes observed during successful MCP inspections.
v0.1.5Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already disclose that the operation is read-only, idempotent, non-destructive, and dependent on an open-world source. The description adds the provider name 'Open Exchange Rates', which is useful context, but it omits API-key requirements, rate limits, or anything about the returned conversion.
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 wasted text. Its brevity is efficient, though it leaves the tool under-specified for its parameter complexity.
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 four-parameter conversion tool with 0% schema coverage, no output schema, and many competing currency tools, the description is too thin. It does not explain currency-code expectations, rate source behavior, API-key handling, or what the conversion response contains.
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 carry the burden for all four parameters. It only generically implies converting an amount between two currencies and says nothing about currency-code format, supported currencies, amount units, or the optional api_key parameter.
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 verb and resource: 'Convert a currency amount', and names the data provider. However, it does not distinguish this tool from numerous sibling currency-conversion tools such as frankfurter_convert, exchangerate_convert, or forex_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?
There is no guidance on when to use this tool versus the many alternative exchange-rate and conversion siblings. It does not mention prerequisites, supported currencies, or conditions under which another tool should be preferred.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.