chore: Fixes a few lint error for tools

PiperOrigin-RevId: 797945021

Author: Jacksunwei

src/google/adk/tools/agent_tool.py

@@ -18,8 +18,6 @@
 from typing import TYPE_CHECKING
 
 from google.genai import types
-from pydantic import BaseModel
-from pydantic import ConfigDict
 from pydantic import model_validator
 from typing_extensions import override
 
@@ -164,8 +162,8 @@ async def run_async(
       tool_result = merged_text
     return tool_result
 
-  @classmethod
   @override
+  @classmethod
   def from_config(
       cls, config: ToolArgsConfig, config_abs_path: str
   ) -> AgentTool:

src/google/adk/tools/base_tool.py

@@ -30,7 +30,6 @@
 
 from google.genai import types
 from pydantic import BaseModel
-from pydantic import ConfigDict
 
 from ..utils.variant_utils import get_google_llm_variant
 from ..utils.variant_utils import GoogleLLMVariant
@@ -40,6 +39,7 @@
 
 if TYPE_CHECKING:
   from ..models.llm_request import LlmRequest
+  from .tool_configs import ToolArgsConfig
 
 SelfTool = TypeVar("SelfTool", bound="BaseTool")
 

src/google/adk/utils/variant_utils.py

@@ -39,7 +39,7 @@ class GoogleLLMVariant(Enum):
   """For using API Key from Google AI Studio"""
 
 
-def get_google_llm_variant() -> str:
+def get_google_llm_variant() -> GoogleLLMVariant:
   return (
       GoogleLLMVariant.VERTEX_AI
       if os.environ.get('GOOGLE_GENAI_USE_VERTEXAI', '0').lower()