update-rule · Outlook Assistant MCP: Risk & Policy

WHAT IT DOES

What update-rule does on Outlook Assistant

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

WHY IT NEEDS A POLICY

Why update-rule needs a policy

This tool modifies existing inbox rules, which are configuration settings that control email behavior. While reversible (can be further modified or deleted), this is a Write operation that could significantly impact email management.

From the tool's definition Tool name 'update-rule' and description 'Updates an existing inbox rule' indicate modification of email filtering rules.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update-rule Rate-limited

update-rule 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-rule": {
      "limits": [
        {
          "counter": "update-rule_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 Outlook Assistant, so you can run agents against it safely.

FAQ

Questions about update-rule

What does the update-rule tool do? +

Updates an existing inbox rule. It is categorised as a Write tool in the Outlook Assistant 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-rule? +

Register the Outlook Assistant MCP server in PolicyLayer and add a rule for update-rule: 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 Outlook Assistant. Nothing to install.

What risk level is update-rule? +

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

Can I rate-limit update-rule? +

Yes. Add a rate_limit block to the update-rule 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-rule completely? +

Set action: deny in the PolicyLayer policy for update-rule. 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-rule? +

update-rule is provided by the Outlook Assistant MCP server (titanzero/outlook-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.