update · McFlow MCP: Risk & Policy

WHAT IT DOES

What update does on McFlow

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

WHY IT NEEDS A POLICY

Why update needs a policy

The 'update' tool modifies existing workflow configurations, which falls squarely into the Write category (creates or modifies data reversibly). It is not Read (no data retrieval only), not Execute (does not directly run code/commands, it modifies workflow definitions), not Destructive (changes are reversible via version history or rollback in typical workflow systems), not Financial.

From the tool's definition Tool description states 'Update an existing n8n workflow' — a modification operation on workflow data that is reversible but has significant blast radius if an AI agent modifies critical workflow logic unintentionally.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update Rate-limited

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": {
    "update": {
      "limits": [
        {
          "counter": "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 McFlow, so you can run agents against it safely.

FAQ

Questions about update

What does the update tool do? +

Update an existing n8n workflow. It is categorised as a Write tool in the McFlow 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? +

Register the McFlow MCP server in PolicyLayer and add a rule for 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 McFlow. Nothing to install.

What risk level is update? +

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

Can I rate-limit update? +

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

Set action: deny in the PolicyLayer policy for 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 update? +

update is provided by the McFlow MCP server (mckinleymedia/mcflow-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.