update_phone · CiviCRM MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_phone does on CiviCRM MCP Server

AI agents use update_phone to create or update resources in CiviCRM MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your CiviCRM MCP Server environment.

WHY IT NEEDS A POLICY

Why update_phone needs a policy

The tool modifies contact information reversibly by updating a phone record in CiviCRM. This is a Write action because the change can be undone by updating again to a previous value. It affects contact data but not financial records, and poses medium severity due to potential data integrity issues or contact information tampering if misused by an AI agent.

From the tool's definition Tool description states 'Update an existing phone record' — an explicit write operation that modifies existing data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_phone Rate-limited

update_phone stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "update_phone": {
      "limits": [
        {
          "counter": "update_phone_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches CiviCRM MCP Server, so you can run agents against it safely.

FAQ

Questions about update_phone

What does the update_phone tool do? +

Update an existing phone record. It is categorised as a Write tool in the CiviCRM MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_phone? +

Register the CiviCRM MCP Server MCP server in PolicyLayer and add a rule for update_phone: 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 CiviCRM MCP Server. Nothing to install.

What risk level is update_phone? +

update_phone is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit update_phone? +

Yes. Add a rate_limit block to the update_phone 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 update_phone completely? +

Set action: deny in the PolicyLayer policy for update_phone. 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 update_phone? +

update_phone is provided by the CiviCRM MCP Server MCP server (johncallhub/civicrm-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.