diff --git a/src/halmos/calldata.py b/src/halmos/calldata.py
index d33fca1b..7157b9bc 100644
--- a/src/halmos/calldata.py
+++ b/src/halmos/calldata.py
@@ -153,8 +153,16 @@ def get_dyn_sizes(self, name: str, typ: Type) -> tuple[list[int], BitVecRef]:
 
         return (sizes, size_var)
 
-    def create(self, abi: dict, fun_info: FunctionInfo) -> tuple[ByteVec, list[DynamicParam]]:
-        """Create calldata of the given function"""
+    def create(
+        self, abi: dict, fun_info: FunctionInfo
+    ) -> tuple[ByteVec, list[DynamicParam]]:
+        """
+        Create calldata of the given function.
+
+        Returns:
+            A tuple containing the generated calldata, and the size information
+            for all dynamic parameters included in the calldata.
+        """
 
         # function selector
         calldata = ByteVec()