update_mailbox · Run402 MCP: Risk & Policy

WHAT IT DOES

What update_mailbox does on Run402

AI agents use update_mailbox to create or update resources in Run402 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Run402 environment.

WHY IT NEEDS A POLICY

Why update_mailbox needs a policy

This is a Write operation because it modifies mailbox settings reversibly. The blast radius is medium: misconfigured footer policies could affect email transparency/compliance for projects, potentially exposing or hiding information in email communications. However, no data is deleted, no financial transactions occur, and no code execution is triggered—it simply changes a configuration flag.

From the tool's definition Tool name 'update_mailbox' and description 'Update per-mailbox settings' indicate modification of mailbox configuration. Specifically updates 'footer_policy' setting with options 'run402_transparency' or 'none', which changes email footer behavior.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_mailbox Rate-limited

update_mailbox 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": {
    "update_mailbox": {
      "limits": [
        {
          "counter": "update_mailbox_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 Run402, so you can run agents against it safely.

FAQ

Questions about update_mailbox

What does the update_mailbox tool do? +

Update per-mailbox settings. Currently supports footer_policy: run402_transparency or none. Prototype projects are locked to run402_transparency; attempting none surfaces the gateway. It is categorised as a Write tool in the Run402 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_mailbox? +

Register the Run402 MCP server in PolicyLayer and add a rule for update_mailbox: 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 Run402. Nothing to install.

What risk level is update_mailbox? +

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

Can I rate-limit update_mailbox? +

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

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

update_mailbox is provided by the Run402 MCP server (kychee-com/run402). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.