expire · AWS IoT SiteWise MCP Server MCP: Risk & Policy

WHAT IT DOES

What expire does on AWS IoT SiteWise MCP Server

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

WHY IT NEEDS A POLICY

Why expire needs a policy

This tool modifies data state (key TTL) in a reversible manner. It does not delete data (would be Destructive), nor does it execute arbitrary code or trigger external operations (would be Execute). The severity is medium because misuse could cause unintended expiration of important cached data, but the effect is not instantaneous destruction and can be mitigated by setting new TTLs before expiration occurs.

From the tool's definition "Set an expiration time for a Redis key" - modifies key metadata/TTL without deleting the key itself; operation is reversible by setting a new expiration time or removing the key.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

expire Rate-limited

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": {
    "expire": {
      "limits": [
        {
          "counter": "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 AWS IoT SiteWise MCP Server, so you can run agents against it safely.

FAQ

Questions about expire

What does the expire tool do? +

Set an expiration time for a Redis key. It is categorised as a Write tool in the AWS IoT SiteWise 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 expire? +

Register the AWS IoT SiteWise MCP Server MCP server in PolicyLayer and add a rule for 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 AWS IoT SiteWise MCP Server. Nothing to install.

What risk level is expire? +

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

Can I rate-limit expire? +

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

Set action: deny in the PolicyLayer policy for 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 expire? +

expire is provided by the AWS IoT SiteWise MCP Server MCP server (awslabs.aws-iot-sitewise-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.