feat: add ToolWithInstruction wrapper for tool-specific usage instructions (issue #2515)

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

src/crewai/tools/__init__.py

@@ -1 +1,2 @@
 from .base_tool import BaseTool, tool
+from .tool_with_instruction import ToolWithInstruction

src/crewai/tools/tool_with_instruction.py

@@ -0,0 +1,45 @@
+from typing import Any, List, Optional, Dict, Callable, Union
+
+from pydantic import Field, model_validator
+
+from crewai.tools.base_tool import BaseTool
+from crewai.tools.structured_tool import CrewStructuredTool
+
+
+class ToolWithInstruction(BaseTool):
+    """A wrapper for tools that adds specific usage instructions.
+    
+    This allows users to provide specific instructions on when and how to use a tool,
+    without having to include these instructions in the agent's backstory.
+    
+    Attributes:
+        tool: The tool to wrap
+        instructions: Specific instructions about when and how to use this tool
+        name: Name of the tool (inherited from the wrapped tool)
+        description: Description of the tool (inherited from the wrapped tool with instructions)
+    """
+    
+    name: str = Field(default="", description="Name of the tool")
+    description: str = Field(default="", description="Description of the tool")
+    tool: BaseTool = Field(description="The tool to wrap")
+    instructions: str = Field(description="Instructions about when and how to use this tool")
+    
+    @model_validator(mode="after")
+    def set_tool_attributes(self) -> "ToolWithInstruction":
+        """Set attributes from the wrapped tool."""
+        self.name = self.tool.name
+        self.description = f"{self.tool.description}\nInstructions: {self.instructions}"
+        self.args_schema = self.tool.args_schema
+        return self
+    
+    def _run(self, *args: Any, **kwargs: Any) -> Any:
+        """Run the wrapped tool."""
+        return self.tool._run(*args, **kwargs)
+    
+    def to_structured_tool(self) -> CrewStructuredTool:
+        """Convert this tool to a CrewStructuredTool instance."""
+        structured_tool = self.tool.to_structured_tool()
+        
+        structured_tool.description = f"{structured_tool.description}\nInstructions: {self.instructions}"
+        
+        return structured_tool