Check if phone numbers have WhatsApp
AI agents call check_number to retrieve information from Evolution API WhatsApp MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a simple lookup or verification query against WhatsApp's infrastructure to determine the availability/registration status of phone numbers. It has no side effects, does not modify data, does not execute code or trigger external operations, and does not delete or move money.
From the tool's definition Tool name 'check_number' and description 'Check if phone numbers have WhatsApp' indicate a query operation that retrieves information about whether specific phone numbers are registered on WhatsApp. No modification, deletion, or execution of commands occurs.
Attacks that exploit this kind of access
Check if phone numbers have WhatsApp. It is categorised as a Read tool in the Evolution API WhatsApp MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Evolution API WhatsApp MCP Server MCP server in PolicyLayer and add a rule for check_number: 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 Evolution API WhatsApp MCP Server. Nothing to install.
check_number 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 check_number 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 check_number. 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.
check_number is provided by the Evolution API WhatsApp MCP Server MCP server (luiso2/mcp-evolution-api). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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