HDBSCAN · Neo4j Gds MCP: Risk & Policy

WHAT IT DOES

What HDBSCAN does on Neo4j Gds

AI agents invoke HDBSCAN to trigger actions in Neo4j Gds. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why HDBSCAN needs a policy

This tool runs a graph clustering algorithm on the database. It is an Execute-category tool because it triggers an external computation/operation (graph algorithm execution) on the Neo4j database. It does not merely read static data — it performs a computational operation whose results depend on graph data and parameters.

From the tool's definition 'Perform HDBSCAN clustering on the graph' — executes a complex graph algorithm (Hierarchical Density-Based Spatial Clustering) on a Neo4j database

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

HDBSCAN Rate-limited

HDBSCAN stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "HDBSCAN": {
      "limits": [
        {
          "counter": "hdbscan_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Neo4j Gds, so you can run agents against it safely.

FAQ

Questions about HDBSCAN

What does the HDBSCAN tool do? +

Perform HDBSCAN clustering on the graph. HDBSCAN, which stands for Hierarchical Density-Based Spatial Clustering of Applications with Noise,. It is categorised as a Execute tool in the Neo4j Gds MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on HDBSCAN? +

Register the Neo4j Gds MCP server in PolicyLayer and add a rule for HDBSCAN: 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 Neo4j Gds. Nothing to install.

What risk level is HDBSCAN? +

HDBSCAN is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit HDBSCAN? +

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

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

HDBSCAN is provided by the Neo4j Gds MCP server (neo4j-contrib/gds-agent). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.