diff --git a/sru/almasru.py b/sru/almasru.py
index df882e10c5a769f837f2e4639f13a57881486cdc..6e5be4c1ee48824bef7628c458e3a79fb22f0d76 100644
--- a/sru/almasru.py
+++ b/sru/almasru.py
@@ -27,23 +27,25 @@ from xml.etree.ElementTree import fromstring, Element
 
 
 class SruException(Exception):
-    pass
+    """Base Exception for all SRU related operations."""
 
 
 class NoRecord(SruException):
-    pass
+    """Return Exception if SRU query returns zero records."""
 
 
 class NotUnique(SruException):
-    pass
+    """Return Exception for query of unique records that returns more than one record."""
 
 
 class TooManyRecords(SruException):
-    pass
+    """Return Exception if more than 10k records were found by the query.
+
+    Alma SRU does not support requesting more than 10k records."""
 
 
 class SruDiagnostics(SruException):
-    pass
+    """Return the error that was provided by Alma SRU."""
 
 
 class RecordRetriever: