AI agents use list_set to create or update resources in Amazon Location Service MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Amazon Location Service MCP Server environment.
The description indicates a write operation (setting a value at a specific index), which modifies data reversibly. However, the tool name 'list_set' and its description are ambiguous and inconsistent with the server context (Amazon Location Service MCP), lowering confidence. The description suggests an in-place update of a list element, which is a Write operation.
From the tool's definition Tool description says 'Set value at index in list' — this modifies/writes a value in a list data structure.
Documented attack patterns abuse exactly the kind of access list_set gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Amazon Location Service MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for list_set:
{
"version": "1",
"default": "deny",
"tools": {
"list_set": {
"limits": [
{
"counter": "list_set_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} list_set 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.
Free to start. No card required.
Set value at index in list. It is categorised as a Write tool in the Amazon Location Service MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Amazon Location Service MCP Server MCP server in PolicyLayer and add a rule for list_set: 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 Location Service MCP Server. Nothing to install.
list_set 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_set 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_set. 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_set is provided by the Amazon Location Service MCP Server MCP server (awslabs.aws-location-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Amazon Location Service MCP Server, 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.
805 Amazon Location Service MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.