Phone Validation Skill

Overview

Phone Number Validator works by validating the phone number format and the country code to ensure that the phone number is valid. It uses predefined rules and algorithms to validate the phone number, then returns the validation result.

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as PhoneValidationSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

Tool call

{
  "name": "PhoneValidationSkill",
  "arguments": {
    "number": "816-555-1017",
    "country": "us"
  }
}

You do not name the tool yourself; the model picks it. Asking about 816-555-1017 in the terms this skill covers is enough for it to reach for PhoneValidationSkill on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

Argument	Type	Description
`number`Required	string	The phone number to validate
`country`Required	string	The country code of the phone number (e.g., us, uk) length 2–2

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

Result

{
  "status": "ok",
  "error": null,
  "data": {
    "country": "US",
    "detectedCountry": "US",
    "countryName": "United States",
    "countrycode": 1,
    "numberNational": 8165551017,
    "extension": null,
    "isValid": true,
    "isMobile": true,
    "isVoip": false,
    "isDisposable": false,
    "type": "fixed_line_or_mobile",
    "formatted": {
      "international": "+1 816-555-1017",
      "national": "(816) 555-1017",
      "rfc": "tel:+1-816-555-1017",
      "e164": "+18165551017"
    },
    "riskScore": 0,
    "riskLevel": "low"
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`country`	string	`US`	The country code that was supplied with the request
`detectedCountry`	string	`US`	The ISO country code detected from the number
`countryName`	string	`United States`	Full name of the detected country
`countrycode`	number	`1`	The international dialing/country calling code
`numberNational`	number	`8165551017`	The national (significant) number without the country code
`extension`	object	`null`	The phone extension if present, otherwise null
`isValid`	boolean	`true`	Whether the number is valid for the given country/region
`isMobile`	boolean	`true`	Whether the number is a mobile phone
`isVoip`	boolean	`false`	Whether the number is a VOIP line (common in fraud)
`isDisposable`	boolean	`false`	Whether the number is a known disposable/virtual number
`type`	string	`fixed_line_or_mobile`	Line type: fixed_line, mobile, fixed_line_or_mobile, toll_free, premium_rate, shared_cost, voip, personal_number, pager, uan, or unknown
`formatted`	object	`{…}`
`formatted.international`	string	`+1 816-555-1017`	The number in international format
`formatted.national`	string	`(816) 555-1017`	The number in national format
`formatted.rfc`	string	`tel:+1-816-555-1017`	The number in RFC3966 format
`formatted.e164`	string	`+18165551017`	The number in E.164 format
`riskScore`Premium	number	`0`	Composite 0-100 risk score combining validity, disposable, VOIP and line-type signals (higher is riskier)
`riskLevel`Premium	string	`low`	Risk band derived from the score: low, medium or high

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

Status	What it means
`400` / `422`	The arguments did not validate. The message names the offending one.
`401`	The OAuth session is invalid or expired — reconnect the server.
`403`	Blocked by a key restriction or an IP allow-list. Never a bad identity.
`404`	This skill is not part of VerveKit. Check the catalog.
`429`	Out of credits, or a brief rate limit. The message tells them apart.

A call costs 10 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

User Registration: Use the Phone Number Validator API to validate phone numbers for user registration. Use the data to verify user information and prevent fake accounts
Contact Verification: Verify contacts by using the Phone Number Validator API to validate phone numbers. Use the data to ensure accurate contact information and improve communication
Lead Generation: Generate leads by using the Phone Number Validator API to validate phone numbers. Use the data to qualify leads, improve data quality, and increase conversion rates
Fraud Prevention: Prevent fraud by using the Phone Number Validator API to validate phone numbers. Use the data to detect suspicious activities, verify identities, and protect against scams

Other ways to use Phone Validation Skill

Set up Phone Validation Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

Call it as a REST APIOne HTTPS endpoint and an x-api-key header, with SDKs for Node, Python and .NET.APIVerve →Reference →

Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheets →Reference →

Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.VerveContext →Reference →

Pages that use this skill:

Block fake signupsGuides