search_users

THE RISK

Low Risk

Why search_users needs a policy

This tool retrieves user information based on search criteria (phone numbers, emails, IDs, or names) with no side effects. It performs a query operation that returns data without creating, modifying, deleting, or executing any actions. The server description context of messaging and voice memos does not change the nature of this specific tool, which is purely a read/lookup operation.

From the tool's definition Tool description states 'Search multiple Users by their phone numbers, email addresses, ids or names.' The verb 'Search' and the read-only nature of querying user data without modification indicates a retrieval operation.

Documented attack patterns abuse exactly the kind of access search_users gives an agent:

POLICY

How to control search_users

PolicyLayer is an MCP gateway — it sits between your AI agents and Carbon Voice, and nothing reaches the server without passing your rules. This is the rule we recommend for search_users:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "search_users": {}
  }
}

search_users is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register Carbon Voice — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

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EXPLORE

Related tools and policies

More Carbon Voice tools

Destructive delete_folder Delete a folder by its ID. Deleting a folder will also delete nested folders and all the m Execute run_ai_action Run an AI Action (Prompt) for a message. You can run an AI Action for a message by its ID Execute run_ai_action_for_shared_link Run an AI Action (Prompt) for a shared link. You can run an AI Action for a shared link by Write add_attachments_to_message Add attachments to a message. In order to add attachments to a message, you must provide a Write create_conversation_message Sends a message to an existing conversation or any type with a conversation_id. Write create_direct_message Send a Direct Message (DM) to a User or a Group of Users. Write create_folder Create a new folder. Write create_voicememo_message Create a VoiceMemo Message. In order to create a VoiceMemo Message, you must provide a tra

All 28 Carbon Voice tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about search_users

What does the search_users tool do? +

Search multiple Users by their phone numbers, email addresses, ids or names. It is categorised as a Read tool in the Carbon Voice MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on search_users? +

Register the Carbon Voice MCP server in PolicyLayer and add a rule for search_users: 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 Carbon Voice. Nothing to install.

What risk level is search_users? +

search_users is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit search_users? +

Yes. Add a rate_limit block to the search_users 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.

How do I block search_users completely? +

Set action: deny in the PolicyLayer policy for search_users. 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.

What MCP server provides search_users? +

search_users is provided by the Carbon Voice MCP server (phononx/cv-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Carbon Voice tool call.

Start from Carbon Voice, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →