AI agents call list_credentials to retrieve information from McFlow without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and returns credential metadata (IDs and names). While it performs no write or destructive operations, the severity is raised to 'medium' rather than 'low' because exposed credentials represent authentication secrets that could be sensitive information; an AI agent with access could enumerate and target high-value credentials for downstream credential theft or unauthorized access attempts.
From the tool's definition Tool is named 'list_credentials' and description states it 'List all credentials in n8n' - a retrieval operation returning IDs with no modification.
Attacks that exploit this kind of access
List all credentials in n8n with their IDs - use these IDs in workflow nodes. It is categorised as a Read tool in the McFlow MCP Server, which means it retrieves data without modifying state.
Register the McFlow MCP server in PolicyLayer and add a rule for list_credentials: 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 McFlow. Nothing to install.
list_credentials 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_credentials 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_credentials. 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_credentials is provided by the McFlow MCP server (mckinleymedia/mcflow-mcp). 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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