Check a software choice against requirements before buying. requirements (all optional): units, billing ('monthly'|'annual'), plan_id, budget_month {amount, currency}, needs_monthly_billing, max_commitment_months, needs_free_plan, avoid_cost_traps [quote_only, per_seat, usage_metered, renewal_jump, addons_extra, annual_lock], features [text], addons [ids], usage {id: quantity}, service (price only that part of a vendor's ladder, e.g. eor, contractor, contractor_of_record, global_payroll). Each requirement gets fits / does_not_fit / unknown / conflicting / recheck_needed / not_flagged / mentioned, with evidence. Outcome is no_blocking_requirement_found, blocking_requirement_found or insufficient_evidence; unknown never counts as a fit.