list_insert_before | PolicyLayer

WHAT IT DOES

What list_insert_before does on Amazon ElastiCache Memcached MCP Server

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

WHY IT NEEDS A POLICY

Why list_insert_before needs a policy

The tool inserts a new value into an existing list data structure, which is a write/modification operation. It creates new data within the list but does not delete or irreversibly destroy existing data. The blast radius is medium since it modifies cache data in ElastiCache Memcached, which could affect application behavior if misused.

From the tool's definition Insert value before pivot in list

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

list_insert_before Rate-limited

list_insert_before 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": {
    "list_insert_before": {
      "limits": [
        {
          "counter": "list_insert_before_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 Amazon ElastiCache Memcached MCP Server, so you can run agents against it safely.

FAQ

Questions about list_insert_before

What does the list_insert_before tool do? +

Insert value before pivot in list. It is categorised as a Write tool in the Amazon ElastiCache Memcached 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 list_insert_before? +

Register the Amazon ElastiCache Memcached MCP Server MCP server in PolicyLayer and add a rule for list_insert_before: 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 Amazon ElastiCache Memcached MCP Server. Nothing to install.

What risk level is list_insert_before? +

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

Can I rate-limit list_insert_before? +

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

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

list_insert_before is provided by the Amazon ElastiCache Memcached MCP Server MCP server (awslabs.memcached-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.