Design AutoGen Multi-Agent Architecture

Design a multi-agent system for CRE analysis using AutoGen. Define at least four specialized agents (e.g., Data Fetcher, Financial Modeler, Risk Assessor, Report Writer) with their respective roles and responsibilities. Outline their communication protocols, including how they will pass information, refine tasks, and collaborate to produce a final investment report. Consider using a GroupChat and GroupChatManager for orchestration. Detail the tools each agent might need, such as an API for market data or a financial calculation engine.