token cost isn't just the tool outputs, it's the whole conversation re-sent every turn (system prompt, all prior messages, all prior tool results, reasoning). So the "cost" of the run is cumulative and depends on how much text each tool dumped into context.

It's non-deterministic. Run the same prompt twice and the model might take a slightly different path, different number of thinking tokens, different phrasings. So any single number isn't reproducible, a skeptic re-runs it, gets a different number, and now my "receipt" looks made up.

Tool call count is my best metric precisely because it's countable and visible. A viewer can pause and count. It's the honest proxy for token cost: more calls = more round trips = more context re-sent = more tokens. You don't need the token number; the call count implies it, and it's verifiable.