update_user_data · Playfab MCP: Risk & Policy

WHAT IT DOES

What update_user_data does on Playfab

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

WHY IT NEEDS A POLICY

Why update_user_data needs a policy

This tool creates or modifies player custom data without permanently deleting it, fitting the Write category. Severity is medium because unauthorized updates to player data could affect game state, player experience, or business logic, but the operation is reversible through subsequent updates or restoration.

From the tool's definition Tool name 'update_user_data' and description 'Updates custom data for a player' indicate modification of player data. The verb 'Updates' confirms this is a write operation that modifies existing data reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_user_data Rate-limited

update_user_data 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": {
    "update_user_data": {
      "limits": [
        {
          "counter": "update_user_data_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 Playfab, so you can run agents against it safely.

FAQ

Questions about update_user_data

What does the update_user_data tool do? +

Updates custom data for a player. It is categorised as a Write tool in the Playfab MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_user_data? +

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

What risk level is update_user_data? +

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

Can I rate-limit update_user_data? +

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

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

update_user_data is provided by the Playfab MCP server (@akiojin/playfab-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.