Function: notify_price_change
This tool belongs to the trading system, which allows users to trade stocks, manage their account, and view stock information. Tool description: Notify if there is a significant price change in the stocks.
Parameters: stocks: type: array
items: type: string
description: List of stock symbols to check.
threshold: type: float
description: Percentage change threshold to trigger a notification. 
Required parameters: stocks, threshold
Response: notification: type: string
description: Notification message about the price changes.