A GitHub repository offers a tool that automates the process of rewriting passive-aggressive emails using NLP techniques like BERT for tone detection and GPT-2 fine-tuned with LoRA for rewriting. The tool is designed to enhance communication by generating more polished and professional versions of emails, helping users convey their messages more effectively. By utilizing this tool with just a few lines of code, individuals can improve their email communication style and ensure a positive reception of their messages.