The term "agent" is quite broad. In my definition, an LLM becomes an agent when it utilizes the tool usage option.
ChatGPT is a good example: you ask for an image, and you receive one; you ask for a web search, and the chatbot provides an answer based on that search.
In both cases, the chatbot has the ability to rewrite your query for that tool and is even able to call the tools multiple times based on the previous result.
Comments
The term "agent" is quite broad. In my definition, an LLM becomes an agent when it utilizes the tool usage option.
ChatGPT is a good example: you ask for an image, and you receive one; you ask for a web search, and the chatbot provides an answer based on that search.
In both cases, the chatbot has the ability to rewrite your query for that tool and is even able to call the tools multiple times based on the previous result.