diff --git a/ophyd_devices/epics/devices/eiger9m_csaxs.py b/ophyd_devices/epics/devices/eiger9m_csaxs.py
index 108ac00..6783bd6 100644
--- a/ophyd_devices/epics/devices/eiger9m_csaxs.py
+++ b/ophyd_devices/epics/devices/eiger9m_csaxs.py
@@ -23,10 +23,12 @@ logger = bec_logger.logger
 
 
 class EigerError(Exception):
+    '''Base class for exceptions in this module.'''
     pass
 
 
 class EigerTimeoutError(Exception):
+    '''Raised when the Eiger does not respond in time during unstage.'''
     pass
 
 
diff --git a/ophyd_devices/epics/devices/falcon_csaxs.py b/ophyd_devices/epics/devices/falcon_csaxs.py
index 2fe3b7e..440499b 100644
--- a/ophyd_devices/epics/devices/falcon_csaxs.py
+++ b/ophyd_devices/epics/devices/falcon_csaxs.py
@@ -18,10 +18,12 @@ logger = bec_logger.logger
 
 
 class FalconError(Exception):
+    '''Base class for exceptions in this module.'''
     pass
 
 
 class FalconTimeoutError(Exception):
+    '''Raised when the Falcon does not respond in time during unstage.'''
     pass
 
 
diff --git a/ophyd_devices/epics/devices/pilatus_csaxs.py b/ophyd_devices/epics/devices/pilatus_csaxs.py
index 0ec8780..46fe0b0 100644
--- a/ophyd_devices/epics/devices/pilatus_csaxs.py
+++ b/ophyd_devices/epics/devices/pilatus_csaxs.py
@@ -22,10 +22,12 @@ logger = bec_logger.logger
 
 
 class PilatusError(Exception):
+    """Base class for exceptions in this module."""
     pass
 
 
 class PilatusTimeoutError(Exception):
+    '''Raised when the Pilatus does not respond in time during unstage.'''
     pass