cross_db_query · ThinAir Data MCP: Risk & Policy

WHAT IT DOES

What cross_db_query does on ThinAir Data

AI agents invoke cross_db_query to trigger actions in ThinAir Data. 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 cross_db_query needs a policy

Although the tool returns a result set (suggesting a read-like outcome), it actively *executes* queries across multiple database connections and dialects. The blast radius is high because: (1) the query content is arbitrary and not constrained to SELECT — it could include DML or DDL depending on the database permissions; (2) it spans multiple connections simultaneously, multiplying potential impact; (3) 'federated'…

From the tool's definition "Run a federated query across multiple connections (different dialects)" — the word 'Run' indicates active execution of queries, not merely reading schema or metadata.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cross_db_query Rate-limited

cross_db_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": {
    "cross_db_query": {
      "limits": [
        {
          "counter": "cross_db_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 ThinAir Data, so you can run agents against it safely.

FAQ

Questions about cross_db_query

What does the cross_db_query tool do? +

Run a federated query across multiple connections (different dialects). Returns a unified result set with per-source provenance. [ARCHITECT tier]. It is categorised as a Execute tool in the ThinAir Data MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on cross_db_query? +

Register the ThinAir Data MCP server in PolicyLayer and add a rule for cross_db_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 ThinAir Data. Nothing to install.

What risk level is cross_db_query? +

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

Can I rate-limit cross_db_query? +

Yes. Add a rate_limit block to the cross_db_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 cross_db_query completely? +

Set action: deny in the PolicyLayer policy for cross_db_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 cross_db_query? +

cross_db_query is provided by the ThinAir Data MCP server (thinairtelematics/thinair-data). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.