note_update · MCP Object-Authz Lab MCP: Risk & Policy

WHAT IT DOES

What note_update does on MCP Object-Authz Lab

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

WHY IT NEEDS A POLICY

Why note_update needs a policy

This tool modifies existing data (reversible write operation), placing it in the Write category. Severity is high rather than critical because the action is reversible and does not delete data or move money. However, in a deliberately vulnerable multi-tenant system, unauthorized note updates could expose confidentiality/integrity violations across tenants, elevating severity beyond 'medium'.

From the tool's definition Tool name 'note_update' and description 'Update a note' indicate modification of existing data. The server is explicitly described as 'vulnerable-by-design' for learning object-level authorization (BOLA/IDOR) bugs in multi-tenant environments, meaning this…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

note_update Rate-limited

note_update 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": {
    "note_update": {
      "limits": [
        {
          "counter": "note_update_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 Object-Authz Lab, so you can run agents against it safely.

FAQ

Questions about note_update

What does the note_update tool do? +

Update a note. It is categorised as a Write tool in the MCP Object-Authz Lab MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on note_update? +

Register the MCP Object-Authz Lab MCP server in PolicyLayer and add a rule for note_update: 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 Object-Authz Lab. Nothing to install.

What risk level is note_update? +

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

Can I rate-limit note_update? +

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

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

note_update is provided by the MCP Object-Authz Lab MCP server (wrg-11/mcp-objauthz-lab). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.