neo4j.query · Neo4j MCP Server MCP: Risk & Policy

WHAT IT DOES

What neo4j.query does on Neo4j MCP Server

AI agents invoke neo4j.query to trigger actions in Neo4j MCP Server. 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 neo4j.query needs a policy

While the tool itself can execute any Cypher query (including destructive ones like DELETE or DETACH DELETE), it is classified as Execute rather than Destructive because the category is determined by the tool's primary capability and argument-dependent effects. The tool enables execution of arbitrary Cypher operations whose consequences depend entirely on what query the AI constructs.

From the tool's definition Tool name is 'neo4j.query' with description 'Execute a Cypher query against Neo4j'. The verb 'Execute' combined with 'Cypher query' indicates arbitrary code execution against a database.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

neo4j.query Rate-limited

neo4j.query 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": {
    "neo4j.query": {
      "limits": [
        {
          "counter": "neo4j.query_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 MCP Server, so you can run agents against it safely.

FAQ

Questions about neo4j.query

What does the neo4j.query tool do? +

Execute a Cypher query against Neo4j. It is categorised as a Execute tool in the Neo4j MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on neo4j.query? +

Register the Neo4j MCP Server MCP server in PolicyLayer and add a rule for neo4j.query: 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 MCP Server. Nothing to install.

What risk level is neo4j.query? +

neo4j.query is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit neo4j.query? +

Yes. Add a rate_limit block to the neo4j.query 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 neo4j.query completely? +

Set action: deny in the PolicyLayer policy for neo4j.query. 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 neo4j.query? +

neo4j.query is provided by the Neo4j MCP Server MCP server (vpro1032/neo4j-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.