build_encounter_tool · DM20 Protocol MCP: Risk & Policy

WHAT IT DOES

What build_encounter_tool does on DM20 Protocol

AI agents invoke build_encounter_tool 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 build_encounter_tool needs a policy

Build/generate tools typically execute procedural logic to construct game state artifacts (encounters with enemies, challenges, etc.). While this occurs within a constrained game system rather than arbitrary code execution, it still qualifies as Execute because it triggers external operations whose effects depend on encounter parameters (difficulty, party level, monster selection).

From the tool's definition Tool name 'build_encounter_tool' suggests triggering encounter generation logic; server context indicates it operates within D&D 5e game mechanics and combat systems. Description is empty, limiting definitive classification.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

build_encounter_tool Rate-limited

build_encounter_tool 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": {
    "build_encounter_tool": {
      "limits": [
        {
          "counter": "build_encounter_tool_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 build_encounter_tool

What does the build_encounter_tool tool do? +

build_encounter_tool. 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 build_encounter_tool? +

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

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

Can I rate-limit build_encounter_tool? +

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

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

build_encounter_tool 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.