{
  "tools": [
    {"name": "find_customer", "displayName": "Find customer",
     "description": "Look up a customer by name or email and return its customer_id.",
     "parameters": [{"name": "query", "description": "Customer name or email", "dataType": "string", "required": true}],
     "produces": ["customer_id"]},
    {"name": "get_customer_invoices", "displayName": "List a customer's invoices",
     "description": "List the invoices of one customer, newest first, with status and amount due.",
     "parameters": [{"name": "customer_id", "description": "The customer's id", "dataType": "string", "required": true}]},
    {"name": "refund_invoice", "displayName": "Refund an invoice",
     "description": "Refund a paid invoice fully or partially.",
     "parameters": [{"name": "invoice_id", "description": "The invoice id, e.g. INV-1042", "dataType": "string", "required": true},
                    {"name": "amount", "description": "Amount to refund; omit for a full refund", "dataType": "number", "required": false}],
     "examples": ["give them their money back", "refund INV-1042"]},
    {"name": "create_invoice", "displayName": "Create an invoice",
     "description": "Create and send a new invoice to a customer.",
     "parameters": [{"name": "customer_id", "description": "The customer's id", "dataType": "string", "required": true},
                    {"name": "amount", "description": "Total amount", "dataType": "number", "required": true}]},
    {"name": "change_plan", "displayName": "Change subscription plan",
     "description": "Upgrade or downgrade a customer's subscription plan.",
     "parameters": [{"name": "customer_id", "description": "The customer's id", "dataType": "string", "required": true},
                    {"name": "plan", "description": "Target plan: starter, growth or scale", "dataType": "string", "required": true}]},
    {"name": "cancel_subscription", "displayName": "Cancel subscription",
     "description": "Cancel a customer's subscription at the end of the billing period.",
     "parameters": [{"name": "customer_id", "description": "The customer's id", "dataType": "string", "required": true}]},
    {"name": "export_report", "displayName": "Export revenue report",
     "description": "Export monthly revenue, MRR and churn as a CSV file.",
     "parameters": [{"name": "month", "description": "Month as YYYY-MM", "dataType": "string", "required": true}]},
    {"name": "update_tax_settings", "displayName": "Update tax settings",
     "description": "Change the default tax rate or VAT number on invoices.",
     "parameters": [{"name": "tax_rate", "description": "Tax rate in percent", "dataType": "number", "required": false}],
     "requiredRoles": ["admin"]},
    {"name": "ask_user", "displayName": "Ask the user",
     "description": "Ask the user a clarifying question with optional choices.",
     "parameters": [{"name": "question", "description": "The question", "dataType": "string", "required": true}],
     "core": true}
  ]
}