Fix CI failures and address code review feedback

- Add max_usage_count/current_usage_count to CrewStructuredTool
- Add input validation for positive max_usage_count
- Add reset_usage_count method to BaseTool
- Extract usage limit check into separate method
- Add comprehensive edge case tests
- Add proper type hints throughout
- Fix linting issues

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

tests/tools/test_tool_usage_limit.py

@@ -1,7 +1,8 @@
 import pytest
-from unittest.mock import MagicMock, patch
+from unittest.mock import MagicMock
 
 from crewai.tools import BaseTool, tool
+from crewai.tools.tool_usage import ToolUsage
 
 
 def test_tool_usage_limit():
@@ -66,3 +67,85 @@ def test_default_unlimited_usage():
     
     assert default_tool.max_usage_count is None
     assert default_tool.current_usage_count == 0
+
+
+def test_invalid_usage_limit():
+    """Test that negative usage limits raise ValueError."""
+    class ValidTool(BaseTool):
+        name: str = "Valid Tool"
+        description: str = "A tool with valid usage limit"
+
+        def _run(self, input_text: str) -> str:
+            return f"Processed {input_text}"
+    
+    with pytest.raises(ValueError, match="max_usage_count must be a positive integer"):
+        ValidTool(max_usage_count=-1)
+
+
+def test_reset_usage_count():
+    """Test that reset_usage_count method works correctly."""
+    class LimitedTool(BaseTool):
+        name: str = "Limited Tool"
+        description: str = "A tool with usage limits for testing"
+        max_usage_count: int = 3
+
+        def _run(self, input_text: str) -> str:
+            return f"Processed {input_text}"
+
+    tool = LimitedTool()
+    
+    tool.run(input_text="test1")
+    tool.run(input_text="test2")
+    assert tool.current_usage_count == 2
+    
+    tool.reset_usage_count()
+    assert tool.current_usage_count == 0
+    
+    result = tool.run(input_text="test3")
+    assert result == "Processed test3"
+    assert tool.current_usage_count == 1
+
+
+def test_tool_usage_with_toolusage_class():
+    """Test that ToolUsage class correctly enforces usage limits."""
+    class LimitedTool(BaseTool):
+        name: str = "Limited Tool"
+        description: str = "A tool with usage limits for testing"
+        max_usage_count: int = 2
+
+        def _run(self, input_text: str) -> str:
+            return f"Processed {input_text}"
+
+    tool = LimitedTool()
+    
+    mock_agent = MagicMock()
+    mock_task = MagicMock()
+    mock_tools_handler = MagicMock()
+    
+    tool_usage = ToolUsage(
+        tools=[tool],
+        agent=mock_agent,
+        task=mock_task,
+        tools_handler=mock_tools_handler,
+        function_calling_llm=MagicMock(),
+    )
+    
+    tool_usage._check_tool_repeated_usage = MagicMock(return_value=False)
+    tool_usage._format_result = lambda result: result
+    
+    mock_calling = MagicMock()
+    mock_calling.tool_name = "Limited Tool"
+    mock_calling.arguments = {"input_text": "test"}
+    
+    result1 = tool_usage._check_usage_limit(tool, "Limited Tool")
+    assert result1 is None
+    
+    tool.current_usage_count += 1
+    
+    result2 = tool_usage._check_usage_limit(tool, "Limited Tool")
+    assert result2 is None
+    
+    tool.current_usage_count += 1
+    
+    result3 = tool_usage._check_usage_limit(tool, "Limited Tool")
+    assert "has reached its usage limit of 2 times" in result3