Remove occurrences of value from list. Args: key: The name of the key value: Value to remove count: Number of occurrences to remove (0 for all, positive for left-to-right, negative for right-to-left) Returns: Success message or error message
AI agents use list_remove to create or update resources in AWS — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your AWS environment.
The tool modifies a list data structure by removing elements. This is a Write operation (reversible data modification) rather than Destructive, since the list itself persists and values could be re-inserted. Misuse could cause data loss from a list, warranting medium severity.
From the tool's definition "Remove occurrences of value from list" — modifies a list by deleting specific values, but this is a reversible data modification (values can be re-added)
Documented attack patterns abuse exactly the kind of access list_remove gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and AWS, and nothing reaches the server without passing your rules. This is the rule we recommend for list_remove:
{
"version": "1",
"default": "deny",
"tools": {
"list_remove": {
"limits": [
{
"counter": "list_remove_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}list_remove 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.
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Remove occurrences of value from list. Args: key: The name of the key value: Value to remove count: Number of occurrences to remove (0 for all, positive for left-to-right, negative for right-to-left) Returns: Success message or error message. It is categorised as a Write tool in the AWS MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the AWS MCP server in PolicyLayer and add a rule for list_remove: 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. Nothing to install.
list_remove is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the list_remove 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_remove. 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_remove is provided by the AWS MCP server (@awslabs/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from AWS, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
300 AWS tools catalogued and risk-classified — across an index of 43,000+ MCP servers.