run_neo4j_query · MCP Server MCP: Risk & Policy

WHAT IT DOES

What run_neo4j_query does on MCP Server

AI agents invoke run_neo4j_query to trigger actions in 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 run_neo4j_query needs a policy

The tool's purpose is to execute arbitrary Cypher queries without restriction indicated in the description. While some queries may be read-only, the capability to run *any* Cypher query means the tool can create, modify, or delete nodes and relationships in the graph database. This is an Execute risk because the effects depend entirely on the query argument provided by the caller.

From the tool's definition Tool name 'run_neo4j_query' and description 'Run a Cypher query against the Neo4j database' indicate execution of arbitrary Cypher queries.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

run_neo4j_query Rate-limited

run_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": {
    "run_neo4j_query": {
      "limits": [
        {
          "counter": "run_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 MCP Server, so you can run agents against it safely.

FAQ

Questions about run_neo4j_query

What does the run_neo4j_query tool do? +

Run a Cypher query against the Neo4j database. It is categorised as a Execute tool in the 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 run_neo4j_query? +

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

What risk level is run_neo4j_query? +

run_neo4j_query is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit run_neo4j_query? +

Yes. Add a rate_limit block to the run_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 run_neo4j_query completely? +

Set action: deny in the PolicyLayer policy for run_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 run_neo4j_query? +

run_neo4j_query is provided by the MCP Server MCP server (namto908/mcp_server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.