Annotations and intellisense of parameters of custom functions in Excel

Question

I'm making custom functions in Excel by JavaScript API.

I added a function as follows.

/**
 * Add two numbers
 * @customfunction
 * @param {number} first First number
 * @param {number} second Second number
 * @returns {number} The sum of the two numbers.
 */
export function add(first, second) {
  return first + second;
}

I can see that Add two numbers is displayed in the following case. However, I don't see where annotations such as first, second, First number, Second number, The sum of the two numbers. are displayed. Does anyone know what's their purpose?

Additionally, what is useful is the intellisense of parameters of a function as follows, does anyone know how to enable this for custom functions?