Building a custom CLI coding agent using the Pydantic-AI framework allows developers to create tailored tools that fit their specific project needs, unlike general commercial solutions. The article details the architecture, capabilities, and advantages of developing an agent that can perform tasks such as code analysis, running tests, and making updates, emphasizing the importance of understanding the underlying technology. With features like sandboxed execution and up-to-date documentation access, this agent enhances productivity and aligns with best development practices.