memory_supersede · MCP Memory System MCP: Risk & Policy

WHAT IT DOES

What memory_supersede does on MCP Memory System

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

WHY IT NEEDS A POLICY

Why memory_supersede needs a policy

The tool updates an existing memory entry in-place while keeping the same key, which is a reversible modification of stored data. This is a Write operation. Severity is medium because overwriting decisions/rules that guide AI behavior across sessions could have meaningful downstream effects, but the operation appears reversible (prior values could be restored or re-saved).

From the tool's definition 既存判断を更新（同一key維持） — 'update existing decision (maintaining same key)'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

memory_supersede Rate-limited

memory_supersede 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": {
    "memory_supersede": {
      "limits": [
        {
          "counter": "memory_supersede_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 MCP Memory System, so you can run agents against it safely.

FAQ

Questions about memory_supersede

What does the memory_supersede tool do? +

既存判断を更新（同一key維持）. It is categorised as a Write tool in the MCP Memory System MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on memory_supersede? +

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

What risk level is memory_supersede? +

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

Can I rate-limit memory_supersede? +

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

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

memory_supersede is provided by the MCP Memory System MCP server (workerportfolio/mcp-memory-system). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.