Summary of https://cdn.openai.com/business-guides-and-resources/a-practical-guide-to-building-agents.pdf

Practical guide explains that agents are advanced systems utilizing large language models (LLMs) to independently perform multi-step workflows by leveraging tools. It identifies suitable applications for agents in scenarios involving complex decisions, unstructured data, or unwieldy rule-based systems, emphasizing that simpler LLM applications are not considered agents.

The document outlines the fundamental components of an agent as an LLM model, external tools for interaction, and explicit instructions. It also explores orchestration patterns, from single-agent systems to more complex multi-agent architectures, and stresses the importance of robust guardrails and planning for human intervention to ensure safe and reliable agent operation.