OpenAI shipped GPT-4o in mid-May. Anthropic took tool use generally available across the Claude 3 family at the end of May. Every internal slide deck I have seen since then has the word agent on it twice.
Most of those decks are still describing a chatbot with extra steps. The useful shape is simpler and less glamorous: a model that emits a structured tool call, your code that runs it, a result that goes back into the conversation, and a hard stop when the loop has gone on long enough.