diff --git a/src/caoscrawler/sync_graph.py b/src/caoscrawler/sync_graph.py
index 36ed36d7864059fc8f169000313186af9f1eb4b0..dc97f2c338f3cb354171b6ac65d9106d47b93a5e 100644
--- a/src/caoscrawler/sync_graph.py
+++ b/src/caoscrawler/sync_graph.py
@@ -44,16 +44,24 @@ logger = logging.getLogger(__name__)
 
 
 def _for_each_scalar_value(node: SyncNode, condition: Callable[[Any], bool], kind: str,
-                           value: Any = None):
+                           value: Callable[[Any], Any] = None):
     """ helper function that performs an action on each value element of each property of a node
 
-    The action (remove or set) is performed on each property value of each property: in case on
+    The argument "kind" determines which action is performed on each property value:
+    The action (remove or set) is performed on each property value of each property: in case of
     lists, it is performed on each list element. The action is only performed if the condition that
     is provided is fulfilled, i.e. the callable ``condition`` returns True. The callable
     ``condition`` must take the property value (or list element) as the sole argument.
 
     Thus, with "remove" you can conditionally remove values and with "set" you can conditionally
-    replace values
+    replace values.
+
+    Args:
+        node (SyncNode): The node which provides the properties (and their values) to operate on.
+        condition (Callable): A function with one argument which is interpreted as a condition: Only if
+                              it returns True for the property value, the action is executed.
+        kind (str): Either "remove" or "set" depending on whether you want to remove the property or replace the property.
+        value (Callable): A function returning a new value that is set as the property value. This function receives the old value as the single argument.
     """
     for p in node.properties:
         if isinstance(p.value, list):