set_default_smime_info · Gmail MCP Server MCP: Risk & Policy

WHAT IT DOES

What set_default_smime_info does on Gmail MCP Server

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

WHY IT NEEDS A POLICY

Why set_default_smime_info needs a policy

This tool creates or modifies S/MIME configuration for email sending aliases. While it affects security-sensitive email settings, it does not delete data (not Destructive), execute arbitrary code (not Execute), or move money (not Financial). It is a Write operation because configuration changes are reversible.

From the tool's definition 'Sets the default S/MIME config' — modifies configuration settings for a send-as alias, which is reversible (can be updated or reconfigured later).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_default_smime_info Rate-limited

set_default_smime_info 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_smime_info": {
      "limits": [
        {
          "counter": "set_default_smime_info_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 Gmail MCP Server, so you can run agents against it safely.

FAQ

Questions about set_default_smime_info

What does the set_default_smime_info tool do? +

Sets the default S/MIME config for the specified send-as alias. It is categorised as a Write tool in the Gmail 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 set_default_smime_info? +

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

What risk level is set_default_smime_info? +

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

Can I rate-limit set_default_smime_info? +

Yes. Add a rate_limit block to the set_default_smime_info 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_smime_info completely? +

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

set_default_smime_info is provided by the Gmail MCP Server MCP server (nk900600/gmail-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.