save_memory · Arvo MCP Server MCP: Risk & Policy

WHAT IT DOES

What save_memory does on Arvo MCP Server

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

WHY IT NEEDS A POLICY

Why save_memory needs a policy

This tool creates or modifies notes in a memory system without destructive effects. The data being written is metadata about user preferences and goals within a fitness coaching context, with no blast radius beyond potentially storing inaccurate information.

From the tool's definition Tool description states 'Save a note to AI memory' - the verb 'Save' indicates creation/modification of data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

save_memory Rate-limited

save_memory 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_memory": {
      "limits": [
        {
          "counter": "save_memory_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 Arvo MCP Server, so you can run agents against it safely.

FAQ

Questions about save_memory

What does the save_memory tool do? +

Save a note to AI memory for future reference. Use to remember important user preferences, goals, or context. It is categorised as a Write tool in the Arvo MCP Server 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_memory? +

Register the Arvo MCP Server MCP server in PolicyLayer and add a rule for save_memory: 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 Arvo MCP Server. Nothing to install.

What risk level is save_memory? +

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

Can I rate-limit save_memory? +

Yes. Add a rate_limit block to the save_memory 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_memory completely? +

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

save_memory is provided by the Arvo MCP Server MCP server (khaoss85/arvo-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.