validate_identifier
utilpeek: check the format and check digits of an identifier. For a VIN's vehicle use decode_vin; for phone numbers use parse_phone_number. Returns valid, reason (invalid_checksum, invalid_length, invalid_format, ... when not valid), compact, formatted and a kind-specific detail (an IBAN's countr...
This record as markdown: /tools/dev-tanod-tanod/validate-identifier.md
What validate_identifier does on Tanod
AI agents call validate_identifier to retrieve information from Tanod without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
kind | string | Yes | Identifier kind: iban, bic, vat (EU, format only, no VIES), isbn, issn, ean, isin, lei, imo, luhn (generic mod-10), or a national format (au_abn, br_cnpj, br_cp |
value | string | Yes | The identifier (1-64 printable ASCII characters). |
Parameters from the server's own tool schema.
Why validate_identifier is rated Low
Even though validate_identifier only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
The rule that runs validate_identifier safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Tanod, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For validate_identifier, this is the rule to start with:
validate_identifier is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Tanod, apply this rule, and every validate_identifier call is checked against it from then on.
Questions about validate_identifier
utilpeek: check the format and check digits of an identifier. For a VIN's vehicle use decode_vin; for phone numbers use parse_phone_number. Returns valid, reason (invalid_checksum, invalid_length, invalid_format, ... when not valid), compact, formatted and a kind-specific detail (an IBAN's country and bank code, an ISBN's ISBN-10/13 forms, ...). An invalid identifier is a normal answer (charged); a malformed request is a 422 (not charged). Checks format and check digits only, offline (python-stdnum): a valid result does not mean the identifier exists or is registered (no registry, bank or VIES call). Payment card numbers are not accepted, not even under luhn. The submitted value is processed in memory only, never logged or stored. Typically under 0.1 s. Price: USD 0.001. Free: 10 utilpeek calls per IP per UTC day. Docs: https://tanod.dev/learn/iban-validation-api.html. It is categorised as a Read tool in the Tanod MCP Server, which means it retrieves data without modifying state.
validate_identifier accepts 2 parameters: kind, value. Required: kind, value. The full parameter table on this page comes from the server's own tool schema.
Register the Tanod MCP server in PolicyLayer and add a rule for validate_identifier: 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 Tanod. Nothing to install.
validate_identifier 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 validate_identifier 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 validate_identifier. 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.
validate_identifier is provided by the Tanod MCP server (https://tanod.dev/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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