Fix tool schema generation for variadic parameters

llama-index-core/llama_index/core/tools/utils.py

@@ -1,4 +1,4 @@
-from inspect import signature
+from inspect import Parameter, signature
 from typing import (
     Any,
     Awaitable,
@@ -40,6 +40,11 @@ def create_schema_from_function(
     for param_name in params:
         if param_name in ignore_fields:
             continue
+        if params[param_name].kind in (
+            Parameter.VAR_POSITIONAL,
+            Parameter.VAR_KEYWORD,
+        ):
+            continue
 
         param_type = params[param_name].annotation
         param_default = params[param_name].default

llama-index-core/tests/tools/test_utils.py

@@ -32,6 +32,19 @@ def test_fn2(x: int = 1) -> None:
     assert "required" not in schema
 
 
+def test_create_schema_from_function_ignores_variadic_parameters() -> None:
+    """Test that *args and **kwargs are not exposed as tool parameters."""
+
+    def test_fn(query: str, *args: str, **kwargs: str) -> None:
+        """Test variadic inputs."""
+
+    SchemaCls = create_schema_from_function("test_schema", test_fn)
+    schema = SchemaCls.model_json_schema()
+
+    assert schema["properties"] == {"query": {"title": "Query", "type": "string"}}
+    assert schema["required"] == ["query"]
+
+
 def test_create_schema_from_function_with_field() -> None:
     """Test create_schema_from_function with pydantic.Field."""