AI agents call list_workspace_users to retrieve information from MCP Google Contacts Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves/queries user information from a Google Workspace directory without modifying data. It is a Read operation. Severity is medium because it exposes potentially sensitive organizational user information (names, emails, roles) that could be used for reconnaissance, social engineering, or privacy violations if exposed to an unauthorized agent, but it carries no destructive or financial risk.
From the tool's definition Tool name 'list_workspace_users' indicates data retrieval from a Google Workspace directory; server description confirms it provides tools for 'search Google Workspace directories' with listing capability.
Documented attack patterns abuse exactly the kind of access list_workspace_users gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP Google Contacts Server, and nothing reaches the server without passing your rules. This is the rule we recommend for list_workspace_users:
{
"version": "1",
"default": "deny",
"tools": {
"list_workspace_users": {}
}
}list_workspace_users is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
list_workspace_users. It is categorised as a Read tool in the MCP Google Contacts Server MCP Server, which means it retrieves data without modifying state.
Register the MCP Google Contacts Server MCP server in PolicyLayer and add a rule for list_workspace_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 MCP Google Contacts Server. Nothing to install.
list_workspace_users is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the list_workspace_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.
Set action: deny in the PolicyLayer policy for list_workspace_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.
list_workspace_users is provided by the MCP Google Contacts Server MCP server (rayanzaki/mcp-google-contacts-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 9 MCP Google Contacts Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
9 MCP Google Contacts Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.