Mark make_default_short_help as private API

CHANGES.rst

@@ -21,6 +21,7 @@ Unreleased
     ``pytest-xdist`` to detect test pollution and race conditions. :pr:`3151`
 -   Add contributor documentation for running stress tests, randomized
     parallel tests, and Flask smoke tests. :pr:`3151` :pr:`3177`
+-   Mark ``make_default_short_help`` as private API. :issue:`3189` :pr:`3250`
 -   ``CliRunner``'s redirected streams now expose the original file descriptor
     via ``fileno()``, so that ``faulthandler``, ``subprocess``, and other
     C-level consumers no longer crash with ``io.UnsupportedOperation``.

src/click/utils.py

@@ -57,7 +57,10 @@ def make_str(value: t.Any) -> str:
 
 
 def make_default_short_help(help: str, max_length: int = 45) -> str:
-    """Returns a condensed version of help string."""
+    """Returns a condensed version of help string.
+
+    :meta private:
+    """
     # Consider only the first paragraph.
     paragraph_end = help.find("\n\n")