In a C# class with a single constructor, I can add class summary XML documentation and constructor XML documentation:
///
///This class will s
This really is an annoying problem. Another solution I ended up using is to not rely on a primary constructor:
/// Documentation type.
type Awesome =
val sauce : string
/// Documentation constructor.
/// Sauce. Lots of it.
new (sauce) = { sauce = sauce }
More verbose, but no extra files or private constructors needed...