steam_setAchievement · Steam MCP Server MCP: Risk & Policy

WHAT IT DOES

What steam_setAchievement does on Steam MCP Server

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

WHY IT NEEDS A POLICY

Why steam_setAchievement needs a policy

This tool creates or modifies player achievement data reversibly (achievements can be reset in dev/test contexts), making it a Write operation. However, the severity is high because misuse could fraudulently unlock achievements for unauthorized accounts, damage player progression integrity, and violate Steam's terms of service.

From the tool's definition Tool description explicitly states it will 'Set (unlock) an achievement for a player' and requires 'a publisher API key,' indicating it modifies player account data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

steam_setAchievement Rate-limited

steam_setAchievement 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": {
    "steam_setAchievement": {
      "limits": [
        {
          "counter": "steam_setachievement_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 Steam MCP Server, so you can run agents against it safely.

FAQ

Questions about steam_setAchievement

What does the steam_setAchievement tool do? +

Set (unlock) an achievement for a player via the partner API. Intended for dev/test use. Requires a publisher API key with server IP allowlisted in Steamworks partner settings. It is categorised as a Write tool in the Steam 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 steam_setAchievement? +

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

What risk level is steam_setAchievement? +

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

Can I rate-limit steam_setAchievement? +

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

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

steam_setAchievement is provided by the Steam MCP Server MCP server (tmhsdigital/steam-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.