Update app.py

app.py

@@ -103,7 +103,17 @@ class BasicAgent:
             print(f"[{i}] {s[:120]}…")
         state["history"].append({"step": "search", "results": results})
         state["logs"]["search"] = {"query": state["search_query"], "results": results}
-        state["current_step"] = "answer"
+        state["needs_search"] = not results  # Set to True if no results found
+        state["current_step"] = "recheck"
+        return state
+
+    def _re_evaluate(self, state: AgentState) -> AgentState:
+        """If search returned nothing, reformulate a shorter query."""
+        if state["needs_search"]:
+            state["search_query"] = tighten(state["question"])
+            state["current_step"] = "search"
+        else:
+            state["current_step"] = "answer"
         return state
 
     def _extract_boxed_answer(self, text: str) -> str:
@@ -135,17 +145,19 @@ class BasicAgent:
         sg = StateGraph(state_schema=AgentState)
         sg.add_node("analyze", self._analyze_question)
         sg.add_node("search", self._perform_search)
+        sg.add_node("recheck", self._re_evaluate)
         sg.add_node("answer", self._generate_answer)
 
         # transitions
         sg.add_edge("analyze", "search")
         sg.add_edge("analyze", "answer")
-        sg.add_edge("search", "answer")
+        sg.add_edge("search", "recheck")
 
         def router(state: AgentState):
             return state["current_step"]
 
         sg.add_conditional_edges("analyze", router, {"search": "search", "answer": "answer"})
+        sg.add_conditional_edges("recheck", router, {"search": "search", "answer": "answer"})
         sg.set_entry_point("analyze")
         sg.set_finish_point("answer")
         return sg.compile()