Agent Cost-per-Success Analyzer Prompt

From the run log below, compute:
- Total runs, successful runs, success rate.
- Total tokens (input + output) and total cost.
- Cost per successful run (total cost / successful runs) — the metric that matters.
- The failure mode that wastes the most cost (which step do failed runs reach before dying?).
- One change to reduce wasted cost (fail faster? cheaper model for early steps?).

Run log:
{{log}}

Replace the {{fields}} with your own context and tighten the rules to match your domain.