address comments

Author: matthias-springer

mlir/include/mlir/IR/BuiltinTypeInterfaces.td

@@ -26,9 +26,10 @@ def VectorElementTypeInterface : TypeInterface<"VectorElementTypeInterface"> {
     Implementing this interface establishes a contract between this type and the
     vector type, indicating that this type can be used as element of vectors.
 
-    Vector element types are treated as a bag of bits without any assumed
-    structure. The size of an element type must be constant, but it does not
-    necessarily have to be a compile-time constant.
+    Vector element types are atomic and treated as a bag of bits, i.e., they
+    cannot be decomposed into other types at the abstraction level where they
+    appear in vectors. The size of an element type must be constant, but it does
+    not necessarily have to be a compile-time constant.
 
     Note: This type interface is still evolving. It currently has no methods
     and is just used as marker to allow types to opt into being vector elements.