List all environment variables
AI agents call n8n_list_variables to retrieve information from n8n MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and queries environment variables without side effects. While environment variables can contain sensitive information (credentials, API keys), the tool itself performs only a read operation. Severity is medium rather than low because exposure of environment variables could leak credentials or sensitive configuration, but the tool does not execute code, modify data, or cause irreversible damage.
From the tool's definition Tool name 'n8n_list_variables' and description 'List all environment variables' indicate a retrieval operation with no modification or execution.
Attacks that exploit this kind of access
List all environment variables. It is categorised as a Read tool in the n8n MCP Server MCP Server, which means it retrieves data without modifying state.
Register the n8n MCP Server MCP server in PolicyLayer and add a rule for n8n_list_variables: 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 n8n MCP Server. Nothing to install.
n8n_list_variables 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 n8n_list_variables 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 n8n_list_variables. 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.
n8n_list_variables is provided by the n8n MCP Server MCP server (shravan1610/n8n-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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