Validate an EU VAT number against the official VIES register in real time. Confirms current registration for intra-EU trade and, when the member state discloses it, returns the registered business name + address. Covers the 27 EU states (Greece as EL) plus Northern Ireland (XI); Great Britain (GB...
AI agents call tax.vat 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 tool retrieves public business registration data from the EU VIES database. It performs a read-only lookup operation with no side effects, no data modification, and no financial movement. The server charges per call in USDC, but the tool itself does not handle payment or move funds — that is handled by the x402 settlement mechanism at the server level.
From the tool's definition Tool description states it "Validate[s]" and "Confirms current registration" and "returns the registered business name + address" — purely informational queries against the VIES register with no modification, deletion, or financial transaction.
Attacks that exploit this kind of access
Validate an EU VAT number against the official VIES register in real time. Confirms current registration for intra-EU trade and, when the member state discloses it, returns the registered business name + address. Covers the 27 EU states (Greece as EL) plus Northern Ireland (XI); Great Britain (GB) is not in VIES. Pass vat (full identifier like DE811569869) OR country + number. Returns {valid, countryCode, vatNumber, name, address, requestDate, reason}. 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 tax.vat: 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.
tax.vat 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 tax.vat 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 tax.vat. 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.
tax.vat 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 →