refactor: Move BaseTool to main package and centralize tool description generation (#1514)

* move base_tool to main package and consolidate tool desscription generation

* update import path

* update tests

* update doc

* add base_tool test

* migrate agent delegation tools to use BaseTool

* update tests

* update import path for tool

* fix lint

* update param signature

* add from_langchain to BaseTool for backwards support of langchain tools

* fix the case where StructuredTool doesn't have func

---------

Co-authored-by: c0dez <li@vitablehealth.com>
Co-authored-by: Brandon Hancock (bhancock_ai) <109994880+bhancockio@users.noreply.github.com>

tests/tools/test_base_tool.py

@@ -0,0 +1,109 @@
+from typing import Callable
+from crewai.tools import BaseTool, tool
+
+
+def test_creating_a_tool_using_annotation():
+    @tool("Name of my tool")
+    def my_tool(question: str) -> str:
+        """Clear description for what this tool is useful for, you agent will need this information to use it."""
+        return question
+
+    # Assert all the right attributes were defined
+    assert my_tool.name == "Name of my tool"
+    assert (
+        my_tool.description
+        == "Tool Name: Name of my tool\nTool Arguments: {'question': {'description': None, 'type': 'str'}}\nTool Description: Clear description for what this tool is useful for, you agent will need this information to use it."
+    )
+    assert my_tool.args_schema.schema()["properties"] == {
+        "question": {"title": "Question", "type": "string"}
+    }
+    assert (
+        my_tool.func("What is the meaning of life?") == "What is the meaning of life?"
+    )
+
+    # Assert the langchain tool conversion worked as expected
+    converted_tool = my_tool.to_langchain()
+    assert converted_tool.name == "Name of my tool"
+
+    assert (
+        converted_tool.description
+        == "Tool Name: Name of my tool\nTool Arguments: {'question': {'description': None, 'type': 'str'}}\nTool Description: Clear description for what this tool is useful for, you agent will need this information to use it."
+    )
+    assert converted_tool.args_schema.schema()["properties"] == {
+        "question": {"title": "Question", "type": "string"}
+    }
+    assert (
+        converted_tool.func("What is the meaning of life?")
+        == "What is the meaning of life?"
+    )
+
+
+def test_creating_a_tool_using_baseclass():
+    class MyCustomTool(BaseTool):
+        name: str = "Name of my tool"
+        description: str = (
+            "Clear description for what this tool is useful for, you agent will need this information to use it."
+        )
+
+        def _run(self, question: str) -> str:
+            return question
+
+    my_tool = MyCustomTool()
+    # Assert all the right attributes were defined
+    assert my_tool.name == "Name of my tool"
+
+    assert (
+        my_tool.description
+        == "Tool Name: Name of my tool\nTool Arguments: {'question': {'description': None, 'type': 'str'}}\nTool Description: Clear description for what this tool is useful for, you agent will need this information to use it."
+    )
+    assert my_tool.args_schema.schema()["properties"] == {
+        "question": {"title": "Question", "type": "string"}
+    }
+    assert my_tool.run("What is the meaning of life?") == "What is the meaning of life?"
+
+    # Assert the langchain tool conversion worked as expected
+    converted_tool = my_tool.to_langchain()
+    assert converted_tool.name == "Name of my tool"
+
+    assert (
+        converted_tool.description
+        == "Tool Name: Name of my tool\nTool Arguments: {'question': {'description': None, 'type': 'str'}}\nTool Description: Clear description for what this tool is useful for, you agent will need this information to use it."
+    )
+    assert converted_tool.args_schema.schema()["properties"] == {
+        "question": {"title": "Question", "type": "string"}
+    }
+    assert (
+        converted_tool.run("What is the meaning of life?")
+        == "What is the meaning of life?"
+    )
+
+
+def test_setting_cache_function():
+    class MyCustomTool(BaseTool):
+        name: str = "Name of my tool"
+        description: str = (
+            "Clear description for what this tool is useful for, you agent will need this information to use it."
+        )
+        cache_function: Callable = lambda: False
+
+        def _run(self, question: str) -> str:
+            return question
+
+    my_tool = MyCustomTool()
+    # Assert all the right attributes were defined
+    assert not my_tool.cache_function()
+
+
+def test_default_cache_function_is_true():
+    class MyCustomTool(BaseTool):
+        name: str = "Name of my tool"
+        description: str = (
+            "Clear description for what this tool is useful for, you agent will need this information to use it."
+        )
+
+        def _run(self, question: str) -> str:
+            return question
+
+    my_tool = MyCustomTool()
+    # Assert all the right attributes were defined
+    assert my_tool.cache_function()