set_default_account · Email MCP: Risk & Policy

WHAT IT DOES

What set_default_account does on Email

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

WHY IT NEEDS A POLICY

Why set_default_account needs a policy

This tool modifies persistent application state (the default account setting) but does not create, delete, or move actual data. It is reversible (can be changed again), so it is not Destructive. It has no financial impact and does not execute arbitrary code.

From the tool's definition Tool performs state modification by setting a default account preference. The description explicitly states it 'set[s] the default account', which is a write operation that persists configuration state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_default_account Rate-limited

set_default_account 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": {
    "set_default_account": {
      "limits": [
        {
          "counter": "set_default_account_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, so you can run agents against it safely.

FAQ

Questions about set_default_account

What does the set_default_account tool do? +

Set the default account (used when account is omitted). It is categorised as a Write tool in the Email MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_default_account? +

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

What risk level is set_default_account? +

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

Can I rate-limit set_default_account? +

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

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

set_default_account is provided by the Email MCP server (swapnilsurdi/email_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.