Lista todos los usuarios registrados en el sistema
AI agents call listar-usuarios to retrieve information from MCP API 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 displays all registered users in the system. It is a read-only operation that queries data without side effects, matching the Read category definition. Severity is low because listing users is a standard informational query with minimal blast radius—the AI cannot cause harm by misusing this tool unless the user list itself is sensitive, but the operation itself is non-destructive.
From the tool's definition Tool name 'listar-usuarios' and description 'Lista todos los usuarios registrados en el sistema' indicate a list/retrieval operation with no modification, deletion, or execution of code.
Attacks that exploit this kind of access
Lista todos los usuarios registrados en el sistema. It is categorised as a Read tool in the MCP API Server MCP Server, which means it retrieves data without modifying state.
Register the MCP API Server MCP server in PolicyLayer and add a rule for listar-usuarios: 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 API Server. Nothing to install.
listar-usuarios 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 listar-usuarios 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 listar-usuarios. 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.
listar-usuarios is provided by the MCP API Server MCP server (mcgiverdev/mcp-api-v1). 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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