How can I provide intellisense in custom MVC html helper?

Question

I am making a custom MVC html helper that is similar in many ways to the built in ActionLink helper. I noticed that the built in ActionLink helper has intellisense for actionName and controllerName parameters which I find very useful. My question is how can I provide intellisense in a custom html helper I am writing which also has actionName and controllerName parameters? Here is my helper:

public static MvcHtmlString IconLink(this HtmlHelper helper, string glyphName, string actionName, string controllerName, object routeValues, object htmlAttributes)
{
   // Implementation
}

Is there an attribute of some sort I can use to make intellisense apply to certain parameters? What am I missing?

Here is the video of the intellisense displaying available controller actions for actionName parameter: http://screencast.com/t/xWtaBYnp