ISO 4217 currency lookup. Pass code (alphabetic USD or 3-digit numeric 840) or country. Returns alphabetic + numeric code, English name, minor unit (decimal places — JPY 0, USD 2, BHD 3), and countries using it. Bundled authoritative ISO 4217 data.
AI agents call iso.currency to retrieve information from Mcp without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a pure data retrieval tool that queries a static ISO 4217 reference database. It accepts a currency code or country name as input and returns standardized currency metadata. There are no side effects, state changes, code execution, or financial operations.
From the tool's definition Tool performs currency lookup and returns ISO 4217 data (codes, names, minor units, countries). Verbs indicate read-only operations: 'lookup', 'returns'. No modification, deletion, execution, or financial transaction capability described.
Attacks that exploit this kind of access
ISO 4217 currency lookup. Pass code (alphabetic USD or 3-digit numeric 840) or country. Returns alphabetic + numeric code, English name, minor unit (decimal places — JPY 0, USD 2, BHD 3), and countries using it. Bundled authoritative ISO 4217 data. It is categorised as a Read tool in the Mcp MCP Server, which means it retrieves data without modifying state.
Register the MCP server in PolicyLayer and add a rule for iso.currency: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Mcp. Nothing to install.
iso.currency is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the iso.currency rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for iso.currency. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
iso.currency is provided by the MCP server (@2sio/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →