sync_story_state · Narrarium MCP: Risk & Policy

WHAT IT DOES

What sync_story_state does on Narrarium

AI agents use sync_story_state 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 sync_story_state needs a policy

The tool modifies existing data structures (state/current.md and per-chapter snapshots) by refreshing and updating them from chapter resume state_changes. This is a reversible write operation rather than destructive deletion. The manual design and flag-clearing suggest intentional state management.

From the tool's definition Tool performs state refresh/update operations on story state files ('Refresh state/current.md and per-chapter state snapshots') and clears flags ('clears the stale story-state flag'). These are modification operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

sync_story_state Rate-limited

sync_story_state 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": {
    "sync_story_state": {
      "limits": [
        {
          "counter": "sync_story_state_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 sync_story_state

What does the sync_story_state tool do? +

Refresh state/current.md and per-chapter state snapshots from chapter resume state_changes. This stays manual by design and clears the stale story-state flag. 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 sync_story_state? +

Register the Narrarium MCP server in PolicyLayer and add a rule for sync_story_state: 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 sync_story_state? +

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

Can I rate-limit sync_story_state? +

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

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

sync_story_state 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.