graph_unmerge · Graph-Memory MCP: Risk & Policy

WHAT IT DOES

What graph_unmerge does on Graph-Memory

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

WHY IT NEEDS A POLICY

Why graph_unmerge needs a policy

This tool creates two separate entities from one and redistributes edges, which is a structural modification to the knowledge graph. It is reversible in principle (you could re-merge), so it falls under Write rather than Destructive.

From the tool's definition 'Split a falsely merged entity back into two separate entities, redistributing specified edges' — creates new entities and redistributes relationships

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

graph_unmerge Rate-limited

graph_unmerge 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": {
    "graph_unmerge": {
      "limits": [
        {
          "counter": "graph_unmerge_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 Graph-Memory, so you can run agents against it safely.

FAQ

Questions about graph_unmerge

What does the graph_unmerge tool do? +

Split a falsely merged entity back into two separate entities, redistributing specified edges. Use when entity resolution made a mistake (e.g. merged. It is categorised as a Write tool in the Graph-Memory MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on graph_unmerge? +

Register the Graph-Memory MCP server in PolicyLayer and add a rule for graph_unmerge: 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 Graph-Memory. Nothing to install.

What risk level is graph_unmerge? +

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

Can I rate-limit graph_unmerge? +

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

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

graph_unmerge is provided by the Graph-Memory MCP server (stevepridemore/graph-memory). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.