diff --git a/_pytest/hookspec.py b/_pytest/hookspec.py
index d0c3e4aad..113915d2d 100644
--- a/_pytest/hookspec.py
+++ b/_pytest/hookspec.py
@@ -291,4 +291,6 @@ def pytest_exception_interact(node, call, report):
     """
 
 def pytest_enter_pdb():
-    """ called upon pdb.set_trace()"""
+    """ called upon pdb.set_trace(), can be used by plugins to take special
+    action just before the python debugger enters in interactive mode.
+    """
diff --git a/doc/en/writing_plugins.rst b/doc/en/writing_plugins.rst
index 1e9807cf5..f5e4ce66c 100644
--- a/doc/en/writing_plugins.rst
+++ b/doc/en/writing_plugins.rst
@@ -501,7 +501,7 @@ reporting or interaction with exceptions:
 .. autofunction:: pytest_internalerror
 .. autofunction:: pytest_keyboard_interrupt
 .. autofunction:: pytest_exception_interact
-
+.. autofunction:: pytest_enter_pdb
 
 
 Reference of objects involved in hooks