execute_sql_file · Postgres MCP: Risk & Policy

WHAT IT DOES

What execute_sql_file does on Postgres

AI agents invoke execute_sql_file to trigger actions in Postgres. 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 execute_sql_file needs a policy

This tool runs SQL files without inherent restrictions on their contents. While it offers a validateOnly mode for preview, the primary purpose is execution of arbitrary SQL statements. SQL files can contain destructive operations (DROP TABLE, DELETE), data modifications (INSERT, UPDATE), or complex queries with external side effects.

From the tool's definition Tool description states: 'Execute a .sql file from the filesystem' and 'Useful for running migration scripts, schema changes, or data imports.' The tool executes arbitrary SQL code which can include DELETE, DROP, INSERT, UPDATE, or other commands with side…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

execute_sql_file Rate-limited

execute_sql_file 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": {
    "execute_sql_file": {
      "limits": [
        {
          "counter": "execute_sql_file_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 Postgres, so you can run agents against it safely.

FAQ

Questions about execute_sql_file

What does the execute_sql_file tool do? +

Execute a .sql file from the filesystem. Useful for running migration scripts, schema changes, or data imports. Supports transaction mode for atomic execution. Max file size: 50MB. Use validateOnly=true to preview without executing. Use stripPatterns to remove delimiters like. It is categorised as a Execute tool in the Postgres MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on execute_sql_file? +

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

What risk level is execute_sql_file? +

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

Can I rate-limit execute_sql_file? +

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

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

execute_sql_file is provided by the Postgres MCP server (teja-sudo/postgres-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.