list_users

A read tool on the AWS MCP server.

SERVERAWS SOURCE@awslabs/mcp

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity verified Pull the record →

This record as markdown: /tools/aws/list-users.md

WHAT IT DOES

What list_users does on AWS

AI agents call list_users to retrieve information from AWS without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why list_users is rated Low

This tool retrieves or enumerates a list of users, which is a non-destructive query operation. While it may expose sensitive information (user identities), the tool itself performs no side effects. The empty description limits confidence slightly, but the name is unambiguous.

From the tool's definition Tool name 'list_users' indicates a query/retrieval operation. The verb 'list' is a canonical Read operation that returns data about AWS users without modification.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs list_users safely

PolicyLayer is an MCP gateway: it sits between your AI agents and AWS, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For list_users, this is the rule to start with:

list_users Allowed

list_users is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_users": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect AWS, apply this rule, and every list_users call is checked against it from then on.

FAQ

Questions about list_users

What does the list_users tool do? +

list_users is a read tool on the AWS MCP server. It is categorised as a Read tool in the AWS MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_users? +

Register the AWS MCP server in PolicyLayer and add a rule for list_users: 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.

What risk level is list_users? +

list_users is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit list_users? +

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

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

list_users 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.

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