Payoff Strategy Comparison
compare_payoff_strategiesCalculation, not advice. Verify with a professional before acting. Compare avalanche and snowball payoff strategies side-by-side. Pick this to compare avalanche against snowball ordering on the same set of cards; pick calculate_cc_payoff once a strategy is chosen and the need is a single payoff timeline with windfalls or fixed payments.
Returns months, total interest, payoff order, savings, total_balance, weighted_average_apr_pct, monthly_interest_now, and cost_breakdown array. When an arm is not projected to reach a zero balance, the savings.* fields for that arm carry status: "none" with value: null and an explanation, not a number.
savings.strategies_convergence separately discloses the avalanche/snowball arms' own convergence:
"both_converge" (ordinary case),
"worst_never_amortizes" (the losing strategy arm does not reach a zero balance in this projection but the winning arm does, so savings.best_vs_worst_months/interest carry status: "none"), or
"neither_converges" (the WINNING strategy arm does not reach a zero balance either, so no dollar or month figure derived from either strategy arm is reportable).
lower_total_interest_strategy names whichever of avalanche or snowball has the lower total interest, or "tie" when the two arms' total interest and months are exactly equal. A "tie" can co-occur with savings.strategies_convergence="neither_converges". It reports only that comparison, never that either arm pays off.
chart_hints.title and chart_hints.annotations[0].label report a dollar figure only when the comparison they describe is Defined, and otherwise state plainly that no figure is reportable, matching the "none" status on the corresponding savings.* field. Unlike chart_hints, summary and savings.savings_summary hedge rather than decline a figure, and the two always carry the same sentence as each other: when the compared arm does not converge (savings.baseline_never_amortizes=true, or savings.strategies_convergence=worst_never_amortizes) but the winning side still does, both report a figure hedged as a floor, "saves at least $X and N months ..., so the true saving could be higher than reported". Only when strategies_convergence=neither_converges do summary and savings.savings_summary also state that no figure is reportable. No savings.* sentinel object carries a hedged floor in its value key; the only place a floor ever appears is the savings.savings_summary sentence.
This tool carries no domain-shaped warnings[].type entries (unlike calculate_cc_payoff); warnings[] here is exclusively validation disclosures emitted as warnings[].code, e.g. MINIMUM_PAYMENT_NOT_BINDING_IN_BASELINE plus the general portfolio findings (MANY_CARDS, HIGH_CARD_BALANCE, etc.) shared with every card-based tool.
The response includes chart_hints with rendering directives any client can use.
This tool takes no strategy, fixed_payments, full_schedule or per_segment parameter: it always compares avalanche against snowball over the full schedule, so all four are rejected as unknown_parameter.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| cards | Yes | Credit cards to compare, 1 to 20, the same shape calculate_cc_payoff takes. Required: omitting the field answers contract_error MISSING_REQUIRED_FIELD, while an explicit JSON null answers parse_error ("cards is required and must be an array."); the two are not the same rejection. Every card may carry segments[]. Max 100 segments total across all cards in the request. Per-card, per-type caps: 1 purchase, 1 cash_advance, 5 balance_transfer, 1 promotional, 10 installment_plan. | |
| output | No | Valid values: 'summary' (default), 'inline'. summary returns the headline comparison with a data_preview block; inline returns the full payload. | |
| chart_title | No | Override for the chart title. Optional; must not contain an em dash or en dash. Max 120 characters. | |
| apply_rate_cap | No | Whether to cap each card's APR at the regulatory ceiling before simulating. Optional; defaults to false when omitted. | |
| extra_monthly_payment | No | Extra monthly payment in dollars, $0 to $1,000,000,000, applied on top of the required minimums. Optional; defaults to 0 when omitted. |