Create multiple NPCs at once. Use this when populating a location with several characters. Returns all created characters.
AI agents use batch_create_npcs to create or update resources in DMCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your DMCP environment.
This tool modifies game state by creating new character entities, which is a reversible write operation. While it doesn't delete or execute arbitrary code, it does create data that becomes part of the persistent game world. The severity is medium because misuse could clutter the game with unwanted characters, but the impact is contained within the game context and reversible (characters can be deleted or modified).
From the tool's definition The tool creates multiple NPCs at once, as stated in the description: 'Create multiple NPCs'. This is a write operation that generates and stores new data entities (non-player characters) in the game state.
Risk signalsBulk/mass operation — affects multiple targets
Documented attack patterns abuse exactly the kind of access batch_create_npcs gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and DMCP, and nothing reaches the server without passing your rules. This is the rule we recommend for batch_create_npcs:
{
"version": "1",
"default": "deny",
"tools": {
"batch_create_npcs": {
"limits": [
{
"counter": "batch_create_npcs_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}batch_create_npcs 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.
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Create multiple NPCs at once. Use this when populating a location with several characters. Returns all created characters. It is categorised as a Write tool in the DMCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the D MCP server in PolicyLayer and add a rule for batch_create_npcs: 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 DMCP. Nothing to install.
batch_create_npcs is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the batch_create_npcs 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.
Set action: deny in the PolicyLayer policy for batch_create_npcs. 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.
batch_create_npcs is provided by the D MCP server (shawnrushefsky/dmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from DMCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
204 DMCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.