add_contacts · XEM Email MCP Server MCP: Risk & Policy

WHAT IT DOES

What add_contacts does on XEM Email MCP Server

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

WHY IT NEEDS A POLICY

Why add_contacts needs a policy

This tool creates or modifies contact records within a mailing list, which is a reversible write operation. It does not execute arbitrary code, delete data permanently, or move money. Severity is medium because unauthorized bulk contact additions could enable spam campaigns or unauthorized marketing, but the operation itself is reversible and does not cause permanent data loss or financial harm.

From the tool's definition Tool name 'add_contacts' and description 'Add contacts to a mailing list' indicate creation/modification of contact data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_contacts Rate-limited

add_contacts 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": {
    "add_contacts": {
      "limits": [
        {
          "counter": "add_contacts_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 XEM Email MCP Server, so you can run agents against it safely.

FAQ

Questions about add_contacts

What does the add_contacts tool do? +

Add contacts to a mailing list. It is categorised as a Write tool in the XEM Email 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 add_contacts? +

Register the XEM Email MCP Server MCP server in PolicyLayer and add a rule for add_contacts: 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 XEM Email MCP Server. Nothing to install.

What risk level is add_contacts? +

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

Can I rate-limit add_contacts? +

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

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

add_contacts is provided by the XEM Email MCP Server MCP server (mailxem/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.