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>

src/crewai/tools/base_tool.py

@@ -1,5 +1,4 @@
 import asyncio
-import warnings
 from abc import ABC, abstractmethod
 from inspect import signature
 from typing import Any, Callable, Type, get_args, get_origin
@@ -58,6 +57,13 @@ class BaseTool(BaseModel, ABC):
                 },
             },
         )
+        
+    @field_validator("max_usage_count", mode="before")
+    @classmethod
+    def validate_max_usage_count(cls, v: int | None) -> int | None:
+        if v is not None and v <= 0:
+            raise ValueError("max_usage_count must be a positive integer")
+        return v
 
     def model_post_init(self, __context: Any) -> None:
         self._generate_description()
@@ -74,9 +80,15 @@ class BaseTool(BaseModel, ABC):
 
         # If _run is async, we safely run it
         if asyncio.iscoroutine(result):
-            return asyncio.run(result)
+            result = asyncio.run(result)
-
+            
+        self.current_usage_count += 1
+        
         return result
+        
+    def reset_usage_count(self) -> None:
+        """Reset the current usage count to zero."""
+        self.current_usage_count = 0
 
     @abstractmethod
     def _run(
@@ -95,6 +107,8 @@ class BaseTool(BaseModel, ABC):
             args_schema=self.args_schema,
             func=self._run,
             result_as_answer=self.result_as_answer,
+            max_usage_count=self.max_usage_count,
+            current_usage_count=self.current_usage_count,
         )
 
     @classmethod
@@ -255,7 +269,7 @@ def to_langchain(
     return [t.to_structured_tool() if isinstance(t, BaseTool) else t for t in tools]
 
 
-def tool(*args, result_as_answer=False, max_usage_count=None):
+def tool(*args, result_as_answer: bool = False, max_usage_count: int | None = None) -> Callable:
     """
     Decorator to create a tool from a function.
     

src/crewai/tools/structured_tool.py

@@ -23,6 +23,8 @@ class CrewStructuredTool:
         args_schema: type[BaseModel],
         func: Callable[..., Any],
         result_as_answer: bool = False,
+        max_usage_count: int | None = None,
+        current_usage_count: int = 0,
     ) -> None:
         """Initialize the structured tool.
 
@@ -32,6 +34,8 @@ class CrewStructuredTool:
             args_schema: The pydantic model for the tool's arguments
             func: The function to run when the tool is called
             result_as_answer: Whether to return the output directly
+            max_usage_count: Maximum number of times this tool can be used. None means unlimited usage.
+            current_usage_count: Current number of times this tool has been used.
         """
         self.name = name
         self.description = description
@@ -39,6 +43,8 @@ class CrewStructuredTool:
         self.func = func
         self._logger = Logger()
         self.result_as_answer = result_as_answer
+        self.max_usage_count = max_usage_count
+        self.current_usage_count = current_usage_count
 
         # Validate the function signature matches the schema
         self._validate_function_signature()

src/crewai/tools/tool_usage.py

@@ -200,16 +200,16 @@ class ToolUsage:
             None,
         )
 
-        if available_tool and hasattr(available_tool, 'max_usage_count') and available_tool.max_usage_count is not None:
+        usage_limit_error = self._check_usage_limit(available_tool, tool.name)
-            if available_tool.current_usage_count >= available_tool.max_usage_count:
+        if usage_limit_error:
-                try:
+            try:
-                    result = f"Tool '{tool.name}' has reached its usage limit of {available_tool.max_usage_count} times and cannot be used anymore."
+                result = usage_limit_error
-                    self._telemetry.tool_usage_error(llm=self.function_calling_llm)
+                self._telemetry.tool_usage_error(llm=self.function_calling_llm)
-                    result = self._format_result(result=result)
+                result = self._format_result(result=result)
-                    return result
+                return result
-                except Exception:
+            except Exception:
-                    if self.task:
+                if self.task:
-                        self.task.increment_tools_errors()
+                    self.task.increment_tools_errors()
 
         if result is None:
             try:
@@ -313,6 +313,11 @@ class ToolUsage:
 
         if available_tool and hasattr(available_tool, 'current_usage_count'):
             available_tool.current_usage_count += 1
+            if hasattr(available_tool, 'max_usage_count') and available_tool.max_usage_count is not None:
+                self._printer.print(
+                    content=f"Tool '{available_tool.name}' usage: {available_tool.current_usage_count}/{available_tool.max_usage_count}",
+                    color="blue"
+                )
 
         return result
 
@@ -345,6 +350,24 @@ class ToolUsage:
                 calling.arguments == last_tool_usage.arguments
             )
         return False
+        
+    def _check_usage_limit(self, tool: Any, tool_name: str) -> str | None:
+        """Check if tool has reached its usage limit.
+        
+        Args:
+            tool: The tool to check
+            tool_name: The name of the tool (used for error message)
+            
+        Returns:
+            Error message if limit reached, None otherwise
+        """
+        if (
+            hasattr(tool, 'max_usage_count') 
+            and tool.max_usage_count is not None 
+            and tool.current_usage_count >= tool.max_usage_count
+        ):
+            return f"Tool '{tool_name}' has reached its usage limit of {tool.max_usage_count} times and cannot be used anymore."
+        return None
 
     def _select_tool(self, tool_name: str) -> Any:
         order_tools = sorted(

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