[3.12] GH-111963: Clarify sys.monitoring.free_tool_id's limitations (GH-112304)

(cherry picked from commit 46500c4)
Co-authored-by: Tian Gao <[email protected]>

Author: miss-islington

Doc/library/sys.monitoring.rst

@@ -54,6 +54,13 @@ Registering and using tools
 
    Should be called once a tool no longer requires *tool_id*.
 
+.. note::
+
+   :func:`free_tool_id` will not disable global or local events associated
+   with *tool_id*, nor will it unregister any callback functions. This
+   function is only intended to be used to notify the VM that the
+   particular *tool_id* is no longer in use.
+
 .. function:: get_tool(tool_id: int, /) -> str | None
 
    Returns the name of the tool if *tool_id* is in use,