key_expire · Redis MCP: Risk & Policy

WHAT IT DOES

What key_expire does on Redis MCP

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

WHY IT NEEDS A POLICY

Why key_expire needs a policy

This tool modifies Redis key properties (expiration/TTL) without destroying data or executing arbitrary code. It is reversible (expiration can be cancelled or changed), making it a Write operation rather than Destructive. The severity is medium because careless use could inadvertently cause keys to expire, leading to data unavailability, but the impact is localized to individual keys and the action is recoverable.

From the tool's definition Tool name 'key_expire' and description '设置键过期时间' (set key expiration time) indicates modification of key metadata. This is a write operation that alters TTL (time-to-live) attributes of existing keys, which is reversible by resetting the expiration time.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

key_expire Rate-limited

key_expire 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": {
    "key_expire": {
      "limits": [
        {
          "counter": "key_expire_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 Redis MCP, so you can run agents against it safely.

FAQ

Questions about key_expire

What does the key_expire tool do? +

设置键过期时间. It is categorised as a Write tool in the Redis 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 key_expire? +

Register the Redis MCP server in PolicyLayer and add a rule for key_expire: 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 Redis MCP. Nothing to install.

What risk level is key_expire? +

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

Can I rate-limit key_expire? +

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

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

key_expire is provided by the Redis MCP server (pickstar-2002/redis-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.