The llamaindex-cli tool enables users to explore retrieval-augmented generation (RAG) without coding by utilizing Chroma as its underlying technology, requiring users to install both the llama-index and chromadb packages. To operate the tool, users must first set their OpenAI API Key as an environment variable, then ingest local files into a vector database, such as a README.md file, using specific file patterns. Once data is ingested, users can inquire about the content using questions that the tool answers through LlamaIndex, which structures and accesses data for LLM-based applications by integrating retrieval with natural language processing. LlamaIndex provides a cost-effective and reliable alternative to LLM fine-tuning by using data connectors, indexes, and engines, and offers a high-level API for beginners alongside more customizable lower-level APIs for advanced users. Additionally, the tool supports a chat interface within the terminal and allows for model customization, including local models, to enhance query and retrieval techniques.