ms_auth_status · M365 MCP: Risk & Policy

WHAT IT DOES

What ms_auth_status does on M365 MCP

AI agents invoke ms_auth_status to trigger actions in M365 MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why ms_auth_status needs a policy

While primarily checking authentication status (a Read action), the tool also triggers an external side effect — opening a browser for sign-in — which constitutes an Execute-level action. This could be misused to initiate unexpected browser sessions or OAuth flows on the user's machine.

From the tool's definition 'opens browser to sign in' — triggers an external browser operation beyond simple data retrieval

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ms_auth_status Rate-limited

ms_auth_status stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "ms_auth_status": {
      "limits": [
        {
          "counter": "ms_auth_status_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches M365 MCP, so you can run agents against it safely.

FAQ

Questions about ms_auth_status

What does the ms_auth_status tool do? +

Check Microsoft 365 connection status. If not connected, opens browser to sign in. It is categorised as a Execute tool in the M365 MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on ms_auth_status? +

Register the M365 MCP server in PolicyLayer and add a rule for ms_auth_status: 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 M365 MCP. Nothing to install.

What risk level is ms_auth_status? +

ms_auth_status is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit ms_auth_status? +

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

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

ms_auth_status is provided by the M365 MCP server (stumason/m365-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.