save_snapshot · Memory Engine MCP: Risk & Policy

WHAT IT DOES

What save_snapshot does on Memory Engine

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

WHY IT NEEDS A POLICY

Why save_snapshot needs a policy

This tool creates or modifies persistent state data by storing AI agent memory snapshots. While it performs a write operation, it is reversible (not destructive) and has no capability to execute code, move funds, or perform irreversible deletion.

From the tool's definition The tool saves ('保存する') the current NeuroState, biases, and policies as a snapshot. This is a persistent write operation that creates or modifies data (snapshot creation) but is reversible—snapshots can be overwritten or deleted.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

save_snapshot Rate-limited

save_snapshot 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": {
    "save_snapshot": {
      "limits": [
        {
          "counter": "save_snapshot_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 Memory Engine, so you can run agents against it safely.

FAQ

Questions about save_snapshot

What does the save_snapshot tool do? +

現在のNeuroState・バイアス・ポリシーをスナップショットとして保存する。セッション終了時に呼ぶ。. It is categorised as a Write tool in the Memory Engine MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on save_snapshot? +

Register the Memory Engine MCP server in PolicyLayer and add a rule for save_snapshot: 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 Memory Engine. Nothing to install.

What risk level is save_snapshot? +

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

Can I rate-limit save_snapshot? +

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

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

save_snapshot is provided by the Memory Engine MCP server (kagioneko/memory-engine-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.