start_combat · DM20 Protocol MCP: Risk & Policy

WHAT IT DOES

What start_combat does on DM20 Protocol

AI agents invoke start_combat to trigger actions in DM20 Protocol. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why start_combat needs a policy

This tool executes an operational procedure (starting combat) that transitions the game state and triggers dependent mechanical effects (turn order, initiative, ability checks, etc.). While the consequences are reversible (combat can end or be restarted), misuse could disrupt campaign flow, force unintended encounters, or trigger undesired game state changes.

From the tool's definition Tool name: 'start_combat' — initiates a combat encounter, triggering state transitions and game mechanics execution within the D&D campaign system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

start_combat Rate-limited

start_combat stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "start_combat": {
      "limits": [
        {
          "counter": "start_combat_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-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 start_combat

What does the start_combat tool do? +

Start a combat encounter. It is categorised as a Execute tool in the DM20 Protocol MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on start_combat? +

Register the DM20 Protocol MCP server in PolicyLayer and add a rule for start_combat: 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 start_combat? +

start_combat is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit start_combat? +

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

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

start_combat 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.