move_message · Mail Cal Drive MCP: Risk & Policy

WHAT IT DOES

What move_message does on Mail Cal Drive

AI agents use move_message to create or update resources in Mail Cal Drive — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mail Cal Drive environment.

WHY IT NEEDS A POLICY

Why move_message needs a policy

Moving a message changes its organizational state within the email system but does not delete or irreversibly destroy data. This is a write operation with medium severity because misuse could result in emails being moved to inaccessible folders (e.g., spam, deleted items) or incorrect organizational structures, causing data accessibility issues without permanent loss.

From the tool's definition Tool name 'move_message' and description 'Move an email message to a different folder' indicate the tool modifies the location/state of email data. The action is reversible (messages can be moved back), distinguishing it from destructive deletion.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

move_message Rate-limited

move_message 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": {
    "move_message": {
      "limits": [
        {
          "counter": "move_message_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 Mail Cal Drive, so you can run agents against it safely.

FAQ

Questions about move_message

What does the move_message tool do? +

Move an email message to a different folder. It is categorised as a Write tool in the Mail Cal Drive MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on move_message? +

Register the Mail Cal Drive MCP server in PolicyLayer and add a rule for move_message: 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 Mail Cal Drive. Nothing to install.

What risk level is move_message? +

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

Can I rate-limit move_message? +

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

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

move_message is provided by the Mail Cal Drive MCP server (rumbitopi/mail-cal-drive-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.