Critical failures across all dimensions. Tool definitions are severely underdeveloped. execute_skill_action has no visible input schema in source code (schema score 0). plan_flexible_pay_in_four has minimal schema documentation and generic descriptions. Neither tool has descriptions exceeding 20 characters that explain WHEN to use them or what they return. No error handling, no output schema documentation, no parameter validation guidance. Tool names lack clarity on what 'execute_skill_action' actually does. No evidence of idempotency, composition, or security considerations.

• Add explicit input schema to execute_skill_action with typed parameters (e.g., action_type enum, purchase_amount number, user_id string) and descriptions for each.
• Expand tool descriptions to 100-200 characters. For plan_flexible_pay_in_four: 'Plan a Klarna Pay-in-4 payment arrangement. Returns installment schedule, session ID, and checkout token. Use this when a user wants to split a purchase into 4 interest-free payments.'
• Document output schemas for both tools. For plan_flexible_pay_in_four, declare: {klarna_session_id: string, pay_in_4_installments: array of {installment_num, amount_usd, due_date}, interest_apr_pct: number, ai_price_drop_protection_active: boolean, single_click_merchant_checkout_token: string}.
• Add parameter descriptions and constraints. For user_account_tier, specify: 'User account tier (enum: gold, silver, bronze). Determines eligibility and interest rates.' For purchase_total_usd, add: 'Total purchase amount in USD (range: 10 - 10000). Must be a valid number.'
• Implement error handling with actionable messages. E.g., if purchase_total_usd < 10, return: 'Purchase amount too low. Klarna Pay-in-4 requires minimum $10. Consider a different payment method.' If tier is invalid, return: 'Unknown account tier. Valid tiers: gold, silver, bronze.'