Fix lint and type-checker issues

- Add 'cast' import to fix mypy type compatibility error
- Remove unused imports to fix lint warnings
- Add assertions to reproduction script to use agent variables
- All custom tool patterns now work correctly

Co-Authored-By: João <joao@crewai.com>

reproduce_issue_3226.py

@@ -6,7 +6,6 @@ This script tests all the failing patterns mentioned in the issue.
 
 import sys
 import traceback
-from typing import Any
 
 def test_function_tool():
     """Test 1: Function Tool with @tool decorator"""
@@ -20,13 +19,14 @@ def test_function_tool():
             """Fetch logs from New Relic based on query"""
             return f"Logs for query: {query}"
         
-        teacher = Agent(
+        agent = Agent(
             role='CrashFetcher',
             goal='Extract logs',
             backstory='An agent that fetches logs',
             tools=[fetch_logs],
             allow_delegation=False
         )
+        assert len(agent.tools) == 1, f"Expected 1 tool, got {len(agent.tools)}"
         print("✅ Function tool with @tool decorator: SUCCESS")
         return True
     except Exception as e:
@@ -49,13 +49,14 @@ def test_dict_tool():
             'func': fetch_logs_func
         }
         
-        teacher = Agent(
+        agent = Agent(
             role='CrashFetcher',
             goal='Extract logs',
             backstory='An agent that fetches logs',
             tools=[fetch_logs_dict],
             allow_delegation=False
         )
+        assert len(agent.tools) == 1, f"Expected 1 tool, got {len(agent.tools)}"
         print("✅ Dict-based tool: SUCCESS")
         return True
     except Exception as e:
@@ -77,13 +78,14 @@ def test_basetool_class():
             def _run(self, query: str) -> str:
                 return f"Logs for query: {query}"
         
-        teacher = Agent(
+        agent = Agent(
             role='CrashFetcher',
             goal='Extract logs',
             backstory='An agent that fetches logs',
             tools=[FetchLogsTool()],
             allow_delegation=False
         )
+        assert len(agent.tools) == 1, f"Expected 1 tool, got {len(agent.tools)}"
         print("✅ BaseTool class inheritance: SUCCESS")
         return True
     except Exception as e:
@@ -101,13 +103,14 @@ def test_direct_function():
             """Fetch logs from New Relic based on query"""
             return f"Logs for query: {query}"
         
-        teacher = Agent(
+        agent = Agent(
             role='CrashFetcher',
             goal='Extract logs',
             backstory='An agent that fetches logs',
             tools=[fetch_logs],
             allow_delegation=False
         )
+        assert len(agent.tools) == 1, f"Expected 1 tool, got {len(agent.tools)}"
         print("✅ Direct function assignment: SUCCESS")
         return True
     except Exception as e:
@@ -125,7 +128,7 @@ def main():
     results.append(test_basetool_class())
     results.append(test_direct_function())
     
-    print(f"\n=== SUMMARY ===")
+    print("\n=== SUMMARY ===")
     passed = sum(results)
     total = len(results)
     print(f"Tests passed: {passed}/{total}")

src/crewai/agents/agent_builder/base_agent.py

@@ -2,7 +2,7 @@ import uuid
 from abc import ABC, abstractmethod
 from copy import copy as shallow_copy
 from hashlib import md5
-from typing import Any, Callable, Dict, List, Optional, TypeVar
+from typing import Any, Callable, Dict, List, Optional, TypeVar, cast
 
 from pydantic import (
     UUID4,
@@ -25,7 +25,6 @@ from crewai.security.security_config import SecurityConfig
 from crewai.tools.base_tool import BaseTool, Tool
 from crewai.utilities import I18N, Logger, RPMController
 from crewai.utilities.config import process_config
-from crewai.utilities.converter import Converter
 from crewai.utilities.string_utils import interpolate_only
 
 T = TypeVar("T", bound="BaseAgent")
@@ -186,7 +185,7 @@ class BaseAgent(ABC, BaseModel):
                 processed_tools.append(tool_item)
             elif callable(tool_item):
                 if hasattr(tool_item, '__doc__') and tool_item.__doc__:
-                    converted_tool = tool(tool_item)
+                    converted_tool = cast(BaseTool, tool(tool_item))
                     processed_tools.append(converted_tool)
                 else:
                     raise ValueError(

src/crewai/utilities/agent_utils.py

@@ -11,7 +11,6 @@ from crewai.agents.parser import (
 )
 from crewai.llm import LLM
 from crewai.llms.base_llm import BaseLLM
-from crewai.tools import BaseTool as CrewAITool
 from crewai.tools.base_tool import BaseTool
 from crewai.tools.structured_tool import CrewStructuredTool
 from crewai.tools.tool_types import ToolResult

tests/test_custom_tools.py

@@ -4,9 +4,8 @@ This addresses issue #3226 where custom tool registration was broken in CrewAI 0
 """
 
 import pytest
-from typing import Any
 from crewai import Agent
-from crewai.tools import BaseTool, tool, Tool
+from crewai.tools import BaseTool, tool
 
 
 class TestCustomToolPatterns: