create_asset_prompt · Narrarium MCP: Risk & Policy

WHAT IT DOES

What create_asset_prompt does on Narrarium

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

WHY IT NEEDS A POLICY

Why create_asset_prompt needs a policy

The tool creates new markdown files for asset prompts, which is a reversible write operation. While it modifies the repository structure, this is typical content creation with no irreversible consequences, and no financial or code execution implications. Severity is medium because uncontrolled creation of numerous asset files could clutter the repository, though individual operations are easily correctable.

From the tool's definition Tool description states 'Create an asset prompt markdown file', indicating it creates and persists new files in the assets tree without deletion or destructive operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_asset_prompt Rate-limited

create_asset_prompt 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": {
    "create_asset_prompt": {
      "limits": [
        {
          "counter": "create_asset_prompt_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 Narrarium, so you can run agents against it safely.

FAQ

Questions about create_asset_prompt

What does the create_asset_prompt tool do? +

Create an asset prompt markdown file in the canonical assets tree for a book, entity, chapter, or paragraph image. It is categorised as a Write tool in the Narrarium MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_asset_prompt? +

Register the Narrarium MCP server in PolicyLayer and add a rule for create_asset_prompt: 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 Narrarium. Nothing to install.

What risk level is create_asset_prompt? +

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

Can I rate-limit create_asset_prompt? +

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

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

create_asset_prompt is provided by the Narrarium MCP server (narrarium-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.