update_game_state · DM20 Protocol MCP: Risk & Policy

WHAT IT DOES

What update_game_state does on DM20 Protocol

AI agents use update_game_state to create or update resources in DM20 Protocol — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your DM20 Protocol environment.

WHY IT NEEDS A POLICY

Why update_game_state needs a policy

Based on naming convention and context of sibling write operations (add_*, apply_*), this tool most likely creates or modifies D&D campaign state data reversibly. The empty description reduces confidence but does not change the categorization. Severity is medium because misuse could corrupt campaign state, but effects are likely reversible through other game management tools or by reimporting data.

From the tool's definition Tool name 'update_game_state' indicates a state modification operation. Sibling tools like 'add_death_save', 'add_event', 'add_item_to_character', and 'apply_effect' all perform reversible writes to game data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_game_state Rate-limited

update_game_state 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_game_state": {
      "limits": [
        {
          "counter": "update_game_state_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 DM20 Protocol, so you can run agents against it safely.

FAQ

Questions about update_game_state

What does the update_game_state tool do? +

update_game_state. It is categorised as a Write tool in the DM20 Protocol 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_game_state? +

Register the DM20 Protocol MCP server in PolicyLayer and add a rule for update_game_state: 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 DM20 Protocol. Nothing to install.

What risk level is update_game_state? +

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

Can I rate-limit update_game_state? +

Yes. Add a rate_limit block to the update_game_state 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_game_state completely? +

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

update_game_state is provided by the DM20 Protocol MCP server (polloinfilzato/dm20-protocol). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.