add_checkpoint · McFlow MCP: Risk & Policy

WHAT IT DOES

What add_checkpoint does on McFlow

AI agents use add_checkpoint 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 add_checkpoint needs a policy

Adding a checkpoint represents a reversible modification to workflow state and configuration. While checkpoints enable workflow management and recovery, the action itself creates or updates workflow metadata/structure rather than executing arbitrary operations or deleting data.

From the tool's definition Tool description states 'Add a checkpoint save/restore capability to a workflow' — checkpoints are created/modified workflow configuration features. The server enables 'creation, management, and deployment of n8n workflows.'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_checkpoint Rate-limited

add_checkpoint 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": {
    "add_checkpoint": {
      "limits": [
        {
          "counter": "add_checkpoint_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 add_checkpoint

What does the add_checkpoint tool do? +

Add a checkpoint save/restore capability to a 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 add_checkpoint? +

Register the McFlow MCP server in PolicyLayer and add a rule for add_checkpoint: 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 add_checkpoint? +

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

Can I rate-limit add_checkpoint? +

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

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

add_checkpoint 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.