spawn_npc_group · RPG Ledger MCP Server MCP: Risk & Policy

WHAT IT DOES

What spawn_npc_group does on RPG Ledger MCP Server

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

WHY IT NEEDS A POLICY

Why spawn_npc_group needs a policy

The tool generates/creates a group of NPCs from a template, which is a write/create operation that adds new data to the campaign state. It does not appear to execute code or delete data. Severity is medium because spawning NPC groups could affect campaign balance and state, though within an RPG context the blast radius is limited to the game session data.

From the tool's definition 'spawn_npc_group' and 'Wygeneruj grupę NPC na podstawie szablonu' (Generate a group of NPCs based on a template) — creates new NPC entities in the campaign state

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

spawn_npc_group Rate-limited

spawn_npc_group 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": {
    "spawn_npc_group": {
      "limits": [
        {
          "counter": "spawn_npc_group_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 RPG Ledger MCP Server, so you can run agents against it safely.

FAQ

Questions about spawn_npc_group

What does the spawn_npc_group tool do? +

Wygeneruj grupę NPC na podstawie szablonu z data/npc_templates. It is categorised as a Write tool in the RPG Ledger 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 spawn_npc_group? +

Register the RPG Ledger MCP Server MCP server in PolicyLayer and add a rule for spawn_npc_group: 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 RPG Ledger MCP Server. Nothing to install.

What risk level is spawn_npc_group? +

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

Can I rate-limit spawn_npc_group? +

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

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

spawn_npc_group is provided by the RPG Ledger MCP Server MCP server (sepa79/rpg-ledger-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.