Option A: Claude: builds the sheet from agreed rules
Best when: Your warning signs are agreed and the account list is short
What it does: Claude marks each sign per account; you check, then get questions
Strong at: Every mark traceable to a rule and a value
Limit: Claude may skip or misapply a rule; you must check
Free plan: Yes, limited (5-hour session and weekly caps)
Option B: Gemini: one column per agreed sign
Best when: Your table is too big to paste into a chat
What it does: Gemini adds one sign column per rule; you write the notes
Strong at: Formulas stay in a sheet you can read and rerun
Limit: You must read and test the formulas yourself
Free plan: Yes
Option C: ChatGPT: organises owners' notes into a grid
Best when: The signs are judgement calls owners know better than tables
What it does: ChatGPT organises owner notes into a grid and questions
Strong at: Works without a data export; owner knowledge central
Limit: Depends on how complete each owner's notes are
Free plan: Yes, limited (images, voice, deep research, Codex)