generate_migration · Querybridge MCP: Risk & Policy

WHAT IT DOES

What generate_migration does on Querybridge

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

WHY IT NEEDS A POLICY

Why generate_migration needs a policy

This tool creates or modifies database schema reversibly (Write category). It does not delete data irreversibly (not Destructive), but enables schema changes that could have significant blast radius if misused by an agent (high severity).

From the tool's definition Tool diffs two schemas with source as 'desired state' and target as 'the DB to modify', indicating it generates instructions to alter a database schema.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

generate_migration Rate-limited

generate_migration 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": {
    "generate_migration": {
      "limits": [
        {
          "counter": "generate_migration_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 Querybridge, so you can run agents against it safely.

FAQ

Questions about generate_migration

What does the generate_migration tool do? +

Diff two schemas (source = desired state, target = the DB to modify). It is categorised as a Write tool in the Querybridge MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on generate_migration? +

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

What risk level is generate_migration? +

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

Can I rate-limit generate_migration? +

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

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

generate_migration is provided by the Querybridge MCP server (mahmoudhassanmustafa/querybridge-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.