persist_cache · Self-Improving Memory MCP: Risk & Policy

WHAT IT DOES

What persist_cache does on Self-Improving Memory MCP

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

WHY IT NEEDS A POLICY

Why persist_cache needs a policy

This tool writes data (embedding cache) to persistent storage on disk. It is a write operation that saves in-memory cache state to disk. While reversible in principle (cache can be cleared or overwritten), it modifies the filesystem. Misuse could corrupt cache state or consume disk space, warranting medium severity.

From the tool's definition Persist embedding cache to disk

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

persist_cache Rate-limited

persist_cache 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": {
    "persist_cache": {
      "limits": [
        {
          "counter": "persist_cache_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 Self-Improving Memory MCP, so you can run agents against it safely.

FAQ

Questions about persist_cache

What does the persist_cache tool do? +

Persist embedding cache to disk. It is categorised as a Write tool in the Self-Improving Memory MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on persist_cache? +

Register the Self-Improving Memory MCP server in PolicyLayer and add a rule for persist_cache: 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 Self-Improving Memory MCP. Nothing to install.

What risk level is persist_cache? +

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

Can I rate-limit persist_cache? +

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

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

persist_cache is provided by the Self-Improving Memory MCP server (superpitt/self-improving-memory-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.