dual_update_face · DUAL MCP Server MCP: Risk & Policy

WHAT IT DOES

What dual_update_face does on DUAL MCP Server

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

WHY IT NEEDS A POLICY

Why dual_update_face needs a policy

The tool performs a reversible modification ('Update') to stored data, placing it in the Write category. Severity is medium because unauthorized modification of facial/identity data could enable impersonation, identity fraud, or unauthorized account takeover in a blockchain context, though the exact mechanism and scope are unclear from the minimal description.

From the tool's definition Tool name 'dual_update_face' and description 'Update a face' indicate a modification operation ('Update'). The DUAL system context suggests this likely modifies user profile or identity-related biometric/facial data associated with a blockchain account.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

dual_update_face Rate-limited

dual_update_face 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": {
    "dual_update_face": {
      "limits": [
        {
          "counter": "dual_update_face_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 DUAL MCP Server, so you can run agents against it safely.

FAQ

Questions about dual_update_face

What does the dual_update_face tool do? +

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

How do I enforce a policy on dual_update_face? +

Register the DUAL MCP Server MCP server in PolicyLayer and add a rule for dual_update_face: 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 DUAL MCP Server. Nothing to install.

What risk level is dual_update_face? +

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

Can I rate-limit dual_update_face? +

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

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

dual_update_face is provided by the DUAL MCP Server MCP server (ro-ro-b/dual-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.