claudecron_add_mcp_server · Email MCP Server MCP

WHAT IT DOES

What claudecron_add_mcp_server does on Email MCP Server

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

WHY IT NEEDS A POLICY

Why claudecron_add_mcp_server needs a policy

This tool creates or registers a new MCP server entry in a registry, which is a write operation. While reversible (entries can be removed), it has high severity because misconfigured MCP servers could expose sensitive data or enable unauthorized access to external systems. An AI agent adding malicious servers to the registry could compromise the security posture of the entire Email MCP infrastructure.

From the tool's definition Tool name 'claudecron_add_mcp_server' and description 'Add a new MCP server to registry' indicate creation of a new server registration entry. The verb 'add' combined with 'registry' describes a reversible data modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

claudecron_add_mcp_server Rate-limited

claudecron_add_mcp_server 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": {
    "claudecron_add_mcp_server": {
      "limits": [
        {
          "counter": "claudecron_add_mcp_server_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 Email MCP Server, so you can run agents against it safely.

FAQ

Questions about claudecron_add_mcp_server

What does the claudecron_add_mcp_server tool do? +

Add a new MCP server to registry. It is categorised as a Write tool in the 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 claudecron_add_mcp_server? +

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

What risk level is claudecron_add_mcp_server? +

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

Can I rate-limit claudecron_add_mcp_server? +

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

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

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