auth

THE RISK

Low Risk

Why auth needs a policy

Authentication management could involve reading tokens, writing credentials, or executing auth flows. Without knowing the four actions, it's unclear if this is purely a read/status check or involves token issuance/revocation. The incomplete description lowers confidence significantly.

From the tool's definition Tool name is 'auth' and description says 'Manage authentication with Microsoft Graph. Four simple actions:' — the description is incomplete/uninformative, providing no detail on what the four actions are.

Documented attack patterns abuse exactly the kind of access auth gives an agent:

POLICY

How to control auth

PolicyLayer is an MCP gateway — it sits between your AI agents and Microsoft Graph MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for auth:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "auth": {
      "limits": [
        {
          "counter": "auth_rate",
          "window": "minute",
          "max": 60,
          "scope": "grant"
        }
      ]
    }
  }
}

auth gets a rate cap, and everything else on the server is denied unless you say otherwise.

Create a free account and register Microsoft Graph MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

SET A RULE FOR THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Microsoft Graph MCP Server tools

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All 19 Microsoft Graph MCP Server tools →

Other tools on other servers

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Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Tool risk categories → How PolicyLayer classifies MCP tools by what they can do.
MCP tool → What an MCP tool is and how clients discover and call it.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about auth

What does the auth tool do? +

Manage authentication with Microsoft Graph. Four simple actions:\n\n. It is categorised as a Other tool in the Microsoft Graph MCP Server MCP Server, which means it performs auxiliary operations.

How do I enforce a policy on auth? +

Register the Microsoft Graph MCP Server MCP server in PolicyLayer and add a rule for auth: 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 Microsoft Graph MCP Server. Nothing to install.

What risk level is auth? +

auth is a Other tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit auth? +

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

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

auth is provided by the Microsoft Graph MCP Server MCP server (marlonluo2018/microsoft_graph_mcp_server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Microsoft Graph MCP Server tool call.

Start from Microsoft Graph MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →