toss_get_exchange_rateRetrieves the KRW/USD or USD/KRW exchange rate, optionally for a specified ISO 8601 date and time.
Get KRW/USD or USD/KRW exchange rate. dateTime is optional ISO 8601.
| Name | Required | Description | Default |
|---|---|---|---|
| dateTime | No | ||
| baseCurrency | Yes | ||
| quoteCurrency | Yes |
Changes observed during successful MCP inspections.
v0.3.0Input schema / additionalPropertiesAdded value: +falseInput schema / properties / dateTime / patternPrevious value: -"^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"New value: +"^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, non-destructive, open-world behavior, so the safety profile is covered. The description adds only that dateTime is optional, but doesn't say what the default is (latest rate?) or whether historical dates return an error or nearest value.
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?
Two short, front-loaded sentences with no filler. The purpose comes first and the parameter note second.
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 simple lookup tool with annotations covering safety and an enum-constrained schema, the description is largely sufficient. A brief note on the default behavior when dateTime is omitted would close the remaining gap, especially since no output schema exists.
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 parameter meaning. It does clarify that dateTime is optional and ISO 8601, which helps, but baseCurrency vs quoteCurrency direction is left ambiguous (the 'KRW/USD or USD/KRW' phrasing doesn't map clearly to the two fields).
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?
States a specific verb and resource ('Get ... exchange rate') and names the supported pairs (KRW/USD, USD/KRW), which matches the schema enums and separates it from price/candle siblings. It does not explicitly contrast with neighbors, so it stops short of 5.
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?
Usage is only implied: fetch a current rate, or supply dateTime for a point-in-time rate. There is no statement of when to prefer this over toss_get_prices or other market-data tools, and no exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.