Type Parameters on Scala Macro Annotations

I'm trying to use macro annotations in scala, where my macro annotation would take an argument of another type. It would then use scala reflection to look at the passed in type, and add some methods as appropriate.Eg.

trait MyTrait {
  def x: Int
  def y: Float
}

@MyAnnotation class MyClass //<-- somehow, this annotation should reference MyTrait

class MyAnnotation(val target: Any) extends StaticAnnotation {
  def macroTransform(annottees: Any*) = macro MyAnnotationImpl.impl
}
object MyAnnotationImpl {
  def impl(c: Context)(annottees: c.Expr[Any]*): c.Expr[Any] = {
    // if I can get a handle on the type MyTrait in here
    // then I can call .members on it, etc.
    ...
  }
}

Basically, the same thing as Using Scala reflection in Scala macros, except using macro annotations. However, when I try to template my macro annotation with a TypeTag

class MyAnnotation[T](val target: Any) extends StaticAnnotation {
  def macroTransform[T](annottees: Any*) = macro MyAnnotationImpl.impl[T]
}
object MyAnnotationImpl {
  def impl[T: c.WeakTypeTag](c: Context)(annottees: c.Expr[Any]*): c.Expr[Any] = {
    ...
  }
}

I get

[error] /Users/imran/other_projs/learn_macros/macros/src/main/scala/com/imranrashid/oleander/macros/MacrosWithReflection.scala:7: macro annotation has wrong shape:
[error]   required: def macroTransform(annottees: Any*) = macro ...
[error]   found   : def macroTransform[T](annottees: Any*) = macro ...
[error] class MyAnnotation[T](val target: Any) extends StaticAnnotation {
[error]       ^

I've also tried to make the type an argument to my annotation, so I would use it like @MyAnnotation(MyTrait) class Foo .... I can extract the name as a String with something like

val targetTrait = c.prefix.tree match {
  case Apply(Select(New(Ident(_)), nme.CONSTRUCTOR), List(Ident(termName))) => termName
}

but, I'm not sure what I can do w/ that String to get back the full type. I've also tried variants like @MyAnnotation(typeOf[MyTrait]) class Foo ..., and then use c.eval on the typeOf inside my macro, but that doesn't compile either.