Agentic is such a shitty fucking word to describe how this works that you can tell it was dreamed up by fucking business and marketing idiots.
All of the new "agentic" models talk to themselves and consider it "thinking". It's completely ridiculous. Of course they eat up a lot of tokens, they're fucking chattering with themselves.
There's no way to quantify the amount of "tokens" any given task will take because the "thinking" chatter is verbose and unpredictable as shit. You can send it in a question like "What is happening?" and it burns through a million tokens trying to describe why the latest bash command it tried to run is taking fucking forever because it didn't write the command correctly and it is permanently paused waiting for stdin.