Unless the agent code is open-sourced, there is hardly any transparency in how the agent is spending your tokens and how does it calculate the tokens. It's like asking your lawyer why they charged some amount.
You can insert a proxy in between and look at precisely what it is sending if you’re so inclined
CC accepts http endpoints so doesn’t require anything too complicated
Lawyers can give you a breakdown by the minute in some cases. A better example can be military contracting.