update_tag · MCP Auth MCP: Risk & Policy

WHAT IT DOES

What update_tag does on MCP Auth

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

WHY IT NEEDS A POLICY

Why update_tag needs a policy

This tool creates or modifies data reversibly by updating an existing tag. It does not delete data (which would be Destructive), execute arbitrary code (which would be Execute), or handle financial transactions (Financial). The modification is reversible since updates can be undone by subsequent updates.

From the tool's definition Tool name 'update_tag' and description 'Update a tag' indicate modification of existing data. The sibling tools show a clear CRUD pattern where 'create_tag' (Write), 'delete_tag' (Destructive), and 'update_tag' (this tool) modify tag entities.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_tag Rate-limited

update_tag 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_tag": {
      "limits": [
        {
          "counter": "update_tag_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 MCP Auth, so you can run agents against it safely.

FAQ

Questions about update_tag

What does the update_tag tool do? +

Update a tag. It is categorised as a Write tool in the MCP Auth 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_tag? +

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

What risk level is update_tag? +

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

Can I rate-limit update_tag? +

Yes. Add a rate_limit block to the update_tag 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_tag completely? +

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

update_tag is provided by the MCP Auth MCP server (rubenpenap/mcp-auth). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.