query_ubergraph · Mcp Ubergraph Query MCP: Risk & Policy

WHAT IT DOES

What query_ubergraph does on Mcp Ubergraph Query

AI agents invoke query_ubergraph to trigger actions in Mcp Ubergraph Query. 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 query_ubergraph needs a policy

The tool runs user-supplied SPARQL queries against an external biomedical ontology endpoint. While Ubergraph is a read-oriented knowledge graph and SPARQL is typically used for querying, SPARQL itself supports UPDATE operations that could modify data. The tool description says 'execute' which implies running arbitrary queries.

From the tool's definition 'Execute a SPARQL query against the Ubergraph endpoint' — actively executes arbitrary SPARQL queries against an external endpoint

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

query_ubergraph Rate-limited

query_ubergraph 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": {
    "query_ubergraph": {
      "limits": [
        {
          "counter": "query_ubergraph_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 Ubergraph Query, so you can run agents against it safely.

FAQ

Questions about query_ubergraph

What does the query_ubergraph tool do? +

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

How do I enforce a policy on query_ubergraph? +

Register the Mcp Ubergraph Query MCP server in PolicyLayer and add a rule for query_ubergraph: 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 Ubergraph Query. Nothing to install.

What risk level is query_ubergraph? +

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

Can I rate-limit query_ubergraph? +

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

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

query_ubergraph is provided by the Mcp Ubergraph Query MCP server (twhetzel/mcp-ubergraph-query). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.