First take on a rag tool

tests/rag_tool_test.py

@@ -0,0 +1,21 @@
+from crewai_tools.rag_tool import Adapter, RagTool
+
+
+class MockAdapter(Adapter):
+    answer: str
+
+    def query(self, question: str) -> str:
+        return self.answer
+
+
+def test_rag_tool():
+    adapter = MockAdapter(answer="42")
+    rag_tool = RagTool(adapter=adapter)
+
+    assert rag_tool.name == "Knowledge base"
+    assert (
+        rag_tool.description == "A knowledge base that can be used to answer questions."
+    )
+    assert (
+        rag_tool.run("What is the answer to life, the universe and everything?") == "42"
+    )