fix comment

nullaway/src/main/java/com/uber/nullaway/NullabilityUtil.java

@@ -323,6 +323,10 @@ private static boolean isDirectTypeUseAnnotation(
     // In JSpecify mode and without the LegacyAnnotationLocations flag, annotations on array
     // dimensions are *not* treated as applying to the top-level type, consistent with the JSpecify
     // spec.
+    // Outside of JSpecify mode, annotations which are *not* on the inner type are not treated as
+    // being
+    // applied to the inner type. This can be bypassed the LegacyAnnotationLocations flag, in which
+    // annotations on all locations are treated as applying to the inner type.
     // We don't allow mixing of inner types and array dimensions in the same location
     // (i.e. `Foo.@Nullable Bar []` is meaningless).
     // These aren't correct semantics for type use annotations, but a series of hacky
@@ -342,15 +346,19 @@ private static boolean isDirectTypeUseAnnotation(
           break;
         case ARRAY:
           if (config.isJSpecifyMode() || !config.isLegacyAnnotationLocation()) {
+            // Annotations on array element types do not apply to the top-level
+            // type outside of legacy mode
             return false;
           }
           locationHasArray = true;
           break;
         default:
+          // Wildcard or type argument!
           return false;
       }
     }
     if (config.isLegacyAnnotationLocation()) {
+      // Make sure it's not a mix of inner types and arrays for this annotation's location
       return !(locationHasInnerTypes && locationHasArray);
     }
     if (!hasNestedClass(symbol.type)) {