From 0a669c70162422d5e22774786c28c1265e336b7b Mon Sep 17 00:00:00 2001
From: huanghuoguoguo <1051233107@qq.com>
Date: Sat, 16 May 2026 11:20:32 +0800
Subject: [PATCH] fix(utils): handle missing funcschema parameter docs (#2186)

---
 src/langbot/pkg/utils/funcschema.py       |  2 +-
 tests/unit_tests/utils/test_funcschema.py | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 tests/unit_tests/utils/test_funcschema.py

diff --git a/src/langbot/pkg/utils/funcschema.py b/src/langbot/pkg/utils/funcschema.py
index f18b9e6b..bbe8b77b 100644
--- a/src/langbot/pkg/utils/funcschema.py
+++ b/src/langbot/pkg/utils/funcschema.py
@@ -83,7 +83,7 @@ def get_func_schema(function: typing.Callable) -> dict:
 
         parameters['properties'][param.name] = {
             'type': param_type,
-            'description': args_doc[param.name],
+            'description': args_doc.get(param.name, ''),
         }
 
         # add schema for array
diff --git a/tests/unit_tests/utils/test_funcschema.py b/tests/unit_tests/utils/test_funcschema.py
new file mode 100644
index 00000000..76159851
--- /dev/null
+++ b/tests/unit_tests/utils/test_funcschema.py
@@ -0,0 +1,15 @@
+from langbot.pkg.utils.funcschema import get_func_schema
+
+
+def test_get_func_schema_uses_empty_description_for_undocumented_parameter():
+    def sample_function(documented: str, undocumented: int):
+        """Sample function.
+
+        Args:
+            documented(str): documented parameter description
+        """
+
+    schema = get_func_schema(sample_function)
+
+    assert schema['parameters']['properties']['documented']['description'] == 'documented parameter description'
+    assert schema['parameters']['properties']['undocumented']['description'] == ''