diff --git a/exasol/analytics/query_handler/graph/stage/sql/execution/query_handler_state.py b/exasol/analytics/query_handler/graph/stage/sql/execution/query_handler_state.py
index 19b4e337..96f6b6e5 100644
--- a/exasol/analytics/query_handler/graph/stage/sql/execution/query_handler_state.py
+++ b/exasol/analytics/query_handler/graph/stage/sql/execution/query_handler_state.py
@@ -107,7 +107,7 @@ def _handle_finished_result(
     ) -> ResultHandlerReturnValue:
         """
         We are done with the current node.
-        If there are successors we need to add the final output from this node to the
+        If there are successors, then we need to add the final output from this node to the
         list of inputs of all the successors.
         """
         if self._is_not_last_stage():
diff --git a/exasol/analytics/query_handler/graph/stage/sql/input_output.py b/exasol/analytics/query_handler/graph/stage/sql/input_output.py
index 4a86d857..212ccb1c 100644
--- a/exasol/analytics/query_handler/graph/stage/sql/input_output.py
+++ b/exasol/analytics/query_handler/graph/stage/sql/input_output.py
@@ -8,9 +8,9 @@
 @dataclass(frozen=True)
 class SQLStageInputOutput:
     """
-    This is a type root for a class representing an input/output data for a customer
-    provided node-level query handler - SQLStageQueryHandler. The actual content of
-    the input/output is application specific.
+    This is a type root for a class representing input/output data for a customer
+    provided node-level query handler extending class SQLStageQueryHandler. The actual content of
+    the input/output is application-specific.
     """
     pass
 
diff --git a/exasol/analytics/query_handler/graph/stage/sql/sql_stage.py b/exasol/analytics/query_handler/graph/stage/sql/sql_stage.py
index dd65deb2..50520df8 100644
--- a/exasol/analytics/query_handler/graph/stage/sql/sql_stage.py
+++ b/exasol/analytics/query_handler/graph/stage/sql/sql_stage.py
@@ -12,7 +12,7 @@ class SQLStage(Stage):
     """
     This is a node of an ExecutionGraph.
     Essentially, this is a node-level query handler factory. The query handler
-    itself is user-provided and so is this factory.
+    itself is user-provided and so are the factories implementing this interface.
     """
 
     @abc.abstractmethod