Large Language Model (LLM) agents, powered by advanced AI systems like GPT-4 and Llama, are designed to autonomously handle complex tasks, making their evaluation crucial for ensuring reliability and performance across industries such as healthcare and finance. Unlike traditional model testing that focuses on static metrics, LLM agent evaluation emphasizes interactive, task-oriented behavior in real-time contexts, assessing metrics like task accuracy, robustness, latency, and ethical alignment. Evaluation methods range from automated benchmarks and simulated environments to adversarial and human-in-the-loop testing, each suitable for different development stages to refine agents' capabilities. Building a robust evaluation framework involves defining clear objectives, creating modular components, ensuring repeatability, incorporating automated monitoring, and applying best practices to avoid pitfalls like overfitting and neglecting cost impacts. The future of LLM agent evaluation will be shaped by trends emphasizing standardization, explainability, and ethical practices, ensuring AI systems not only perform effectively but also align with societal values.