disconnect · Sql MCP: Risk & Policy

WHAT IT DOES

What disconnect does on Sql

AI agents use disconnect to create or update resources in Sql — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Sql environment.

WHY IT NEEDS A POLICY

Why disconnect needs a policy

Disconnecting terminates an active database session, which is a reversible state change (you can reconnect). It modifies the connection state without deleting data. While it could disrupt ongoing operations, it's not destructive (no data loss), not an execution of queries, and not a read. Write is the closest category for a reversible state-change action.

From the tool's definition Disconnect from the current database connection. Safe to call when not connected.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

disconnect Rate-limited

disconnect stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "disconnect": {
      "limits": [
        {
          "counter": "disconnect_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about disconnect

What does the disconnect tool do? +

Disconnect from the current database connection. Safe to call when not connected. It is categorised as a Write tool in the Sql MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on disconnect? +

Register the Sql MCP server in PolicyLayer and add a rule for disconnect: 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 Sql. Nothing to install.

What risk level is disconnect? +

disconnect is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit disconnect? +

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

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

disconnect is provided by the Sql MCP server (nakiriyuuzu/sql-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.