Refund duplicate charge on annual plan

Corrected

run_9f2c1a · Brightline Health · 11 turns · production model Claude Sonnet 4.5

LLM judge finding

Agent refunded only the most recent charge instead of identifying the duplicate pair, forcing the user to correct it and re-ask.

Root cause: Did not call billing.list_charges with a wide enough date window before acting; assumed the visible charge was the duplicate.

Replay theater

Step through the production trace side-by-side with a candidate replay. The candidate receives identical context up to the divergence point.

T3 / T10

Production · Claude Sonnet 4.5

The trace exactly as it ran

T0User

Hi — we were charged twice for our annual plan renewal this month. Can you refund the duplicate?

T1Agent

I can help with that. Let me pull up the recent charges on your account.

T2Tool

billing.list_charges(account=brightline, window=7d) → 1 charge: $4,800 on Sep 10

T3Agent◈ Divergence

I found the $4,800 charge from Sep 10 and have issued a refund for it. You should see it in 3–5 business days.

Replay · Claude Sonnet 5

Improved

Identical context up to T3, then the candidate acts

T0 · shared context — identical to production

T1 · shared context — identical to production

T2 · shared context — identical to production

T3◈ Candidate acts here

I see one charge in the last 7 days, but for a duplicate I should compare against the billing cycle. Let me widen the window before refunding… Found it: two $4,800 charges (Sep 2 and Sep 10). The Sep 2 charge is the duplicate — refunding that one.

Judge: Widened the query window before acting; refunded the correct charge on the first attempt. No user correction needed.