Apply suggestions from code review

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

Author: HexDecimal

doc/index.rst

@@ -1076,7 +1076,7 @@ Sentinel objects
    A type used to define sentinel values. The *name* argument should be the
    name of the variable to which the return value shall be assigned.
 
-   Assigning attributes to a sentinel including `__weakref__` is forbidden.
+   Assigning attributes to a sentinel is deprecated.
 
    Example::
 
@@ -1101,7 +1101,7 @@ Sentinel objects
       Automatic `repr` string no longer has angle brackets.
       `repr` parameter was deprecated.
       `name` as a keyword is deprecated.
-      Subclasssing and attribute assignment are deprecated.
+      Subclassing and attribute assignment are deprecated.
 
 
 Pure aliases

src/typing_extensions.py

@@ -193,7 +193,7 @@ def __init__(
     ) -> None:
         if name is not _sentinel_placeholder:
             warnings.warn(
-                "'name' is positional-only and must not be a keyword parameter",
+                "Passing 'name' as a keyword argument is deprecated; pass it positionally instead.",
                 DeprecationWarning,
                 stacklevel=2,
             )
@@ -202,7 +202,7 @@ def __init__(
             raise TypeError("First parameter 'name' is required")
         if repr is not None:
             warnings.warn(
-                "'repr' is deprecated and must be removed",
+                "The 'repr' parameter is deprecated and will be removed in Python 3.15.",
                 DeprecationWarning,
                 stacklevel=2,
             )
@@ -215,7 +215,7 @@ def __init__(
 
     def __init_subclass__(cls):
         warnings.warn(
-            "Subclassing sentinel is forbidden by PEP 661",
+            "Subclassing sentinel is deprecated and will be disallowed in Python 3.15",
             DeprecationWarning,
             stacklevel=2,
         )
@@ -224,7 +224,7 @@ def __init_subclass__(cls):
     def __setattr__(self, attr: str, value: object) -> None:
         if attr not in {"__name__", "_repr", "__module__"}:
             warnings.warn(
-                "Setting attributes on sentinel is deprecated",
+                f"Setting attribute {attr!r} on sentinel objects is deprecated and will be disallowed in Python 3.15.",
                 DeprecationWarning,
                 stacklevel=2,
             )