Trim list to specified range.
AI agents call list_trim to permanently remove resources in AWS IoT SiteWise MCP Server — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Trimming a list to a range typically removes elements outside that range permanently (e.g., like Redis LTRIM). This would be Destructive. However, the description is very brief and ambiguous — it could also be a non-destructive filtering/read operation that returns a subset.
From the tool's definition "Trim list to specified range" — trimming a list implies removing elements outside a specified range, which is a potentially irreversible destructive operation on a data structure.
Attacks that exploit this kind of access
Trim list to specified range. It is categorised as a Destructive tool in the AWS IoT SiteWise MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the AWS IoT SiteWise MCP Server MCP server in PolicyLayer and add a rule for list_trim: 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.
list_trim is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the list_trim 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.
Set action: deny in the PolicyLayer policy for list_trim. 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.
list_trim 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.