user_update · Database MCP Server MCP: Risk & Policy

WHAT IT DOES

What user_update does on Database MCP Server

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

WHY IT NEEDS A POLICY

Why user_update needs a policy

This tool creates or modifies data reversibly by updating user records in the database. It does not delete data (which would be Destructive) nor execute arbitrary code (Execute). The high severity reflects that unauthorized user modifications could compromise user accounts, privacy, or system integrity.

From the tool's definition Tool description states 'Update user fields' with example updates={"name":"Alice"}, which modifies existing user data. The server description mentions 'full CRUD operations' and 'parameterized queries', indicating write capability with some safety controls.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

user_update Rate-limited

user_update 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": {
    "user_update": {
      "limits": [
        {
          "counter": "user_update_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 Database MCP Server, so you can run agents against it safely.

FAQ

Questions about user_update

What does the user_update tool do? +

Update user fields. Example updates={"name":"Alice"}. It is categorised as a Write tool in the Database MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on user_update? +

Register the Database MCP Server MCP server in PolicyLayer and add a rule for user_update: 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 Database MCP Server. Nothing to install.

What risk level is user_update? +

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

Can I rate-limit user_update? +

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

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

user_update is provided by the Database MCP Server MCP server (vrushil1/database-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.