Improve docstring

src/attr/validators.py

@@ -110,16 +110,14 @@ def __repr__(self):
 
 def instance_of(type):
     """
-    A validator that raises a `TypeError` if the initializer is called
-    with a wrong type for this particular attribute (checks are performed using
+    A validator that raises a `TypeError` if the initializer is called with a
+    wrong type for this particular attribute (checks are performed using
     `isinstance` therefore it's also valid to pass a tuple of types).
 
-    :param type: The type to check for.
-    :type type: type or tuple of type
+    :param type | tuple[type] type: The type to check for.
 
-    :raises TypeError: With a human readable error message, the attribute
-        (of type `attrs.Attribute`), the expected type, and the value it
-        got.
+    :raises TypeError: With a human readable error message, the attribute (of
+        type `attrs.Attribute`), the expected type, and the value it got.
     """
     return _InstanceOfValidator(type)