lookup_phone_prefix
utilpeek: Look up a phone number prefix: country, line type and original network, with ambiguity. To parse a full number use parse_phone_number. Returns the country, line type, original network, time zones and E.164 form of the leading digits of a number (0917, +63917, 0063917), ambiguous with ca...
This record as markdown: /tools/dev-tanod-tanod/lookup-phone-prefix.md
What lookup_phone_prefix does on Tanod
AI agents call lookup_phone_prefix 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 |
|---|---|---|---|
list | boolean | — | With `region` (and no prefix): return every mobile prefix of that country at the 4-digit national level (e.g. 0905, 0917), grouped by network. |
prefix | object | — | The leading digits of a number, in any form: 0917, 917, +63917, 0063917 or 63917 (digits with an optional leading + or 00; separators space - . ( ) are ignored) |
region | object | — | ISO 3166-1 alpha-2 country (PH, US, GB, ...): reads a national prefix and selects the country for `list`. |
Parameters from the server's own tool schema.
Why lookup_phone_prefix is rated Low
Even though lookup_phone_prefix 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 lookup_phone_prefix 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 lookup_phone_prefix, this is the rule to start with:
lookup_phone_prefix 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 lookup_phone_prefix call is checked against it from then on.
Questions about lookup_phone_prefix
utilpeek: Look up a phone number prefix: country, line type and original network, with ambiguity. To parse a full number use parse_phone_number. Returns the country, line type, original network, time zones and E.164 form of the leading digits of a number (0917, +63917, 0063917), ambiguous with candidates when they span networks; list with region lists a country's mobile prefixes by network. Input: prefix, optional region to read a national form such as 0917; or list: true with region and no prefix. Original range holder, not the current network (number portability); offline metadata; a national form without region lists candidate countries. Bad input is a 422 (not charged). Typically under 0.1 s. Price: USD 0.001. Free: 10 utilpeek calls per IP per UTC day. The submitted text is never logged or stored. Docs: https://tanod.dev/learn/phone-number-prefix-lookup-api.html. It is categorised as a Read tool in the Tanod MCP Server, which means it retrieves data without modifying state.
lookup_phone_prefix accepts 3 parameters: list, prefix, region. 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 lookup_phone_prefix: 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.
lookup_phone_prefix 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 lookup_phone_prefix 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 lookup_phone_prefix. 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.
lookup_phone_prefix 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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