send_email · Revenue Engine MCP: Risk & Policy

WHAT IT DOES

What send_email does on Revenue Engine MCP

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

WHY IT NEEDS A POLICY

Why send_email needs a policy

This tool creates new data (email messages) and has external side effects (sending emails that reach recipients). It is Write rather than Execute because email sending is a data creation/modification action, not arbitrary code execution. Severity is high because unsupervised email sending could impersonate the user, send spam, disclose sensitive information, or damage professional relationships.

From the tool's definition Tool description: 'Send an email via Gmail.' This creates and sends new email messages, which modifies Gmail account state irreversibly from the user's perspective (sent messages exist permanently).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_email Rate-limited

send_email 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": {
    "send_email": {
      "limits": [
        {
          "counter": "send_email_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 Revenue Engine MCP, so you can run agents against it safely.

FAQ

Questions about send_email

What does the send_email tool do? +

Send an email via Gmail. ALWAYS get user approval before calling this. It is categorised as a Write tool in the Revenue Engine MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on send_email? +

Register the Revenue Engine MCP server in PolicyLayer and add a rule for send_email: 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 Revenue Engine MCP. Nothing to install.

What risk level is send_email? +

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

Can I rate-limit send_email? +

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

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

send_email is provided by the Revenue Engine MCP server (promptishoperations/mcpspec). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.