Update agent.py

agent.py

@@ -127,8 +127,6 @@ gemini_llm = ChatGoogleGenerativeAI(
     model="gemini-2.0-flash",
     temperature=0,
     max_output_tokens=2048,
-).bind_tools(
-    [web_search, wiki_search, parse_csv, parse_excel, python_repl]
 )
 
 # ---------------------------------------------------------------------
@@ -136,33 +134,50 @@ gemini_llm = ChatGoogleGenerativeAI(
 # ---------------------------------------------------------------------
 SYSTEM_PROMPT = SystemMessage(
     content=(
-        "You are a helpful assistant with access to Python tools.\n"
-        "• Think step by step.\n"
-        "• Call a tool when needed – reply in this JSON format:\n"
-        "  {\"tool\": \"<tool_name>\", \"tool_input\": { ... }}\n"
-        "• When you have the answer, reply with the answer **only** "
-        "– no prefix, no explanations.\n"
-        "Answer format rules:\n"
-        "  • Single number → no separators / units unless required.\n"
-        "  • Single string → no articles/abbrev.\n"
-        "  • List  → comma + single space separated, keep required order.\n"
+        "You are a helpful assistant with access to several tools.\n"
+        "You can think step by step and use tools to find answers.\n\n"
+        "When you want to use a tool, write it like this:\n"
+        "Tool: <tool_name>\n"
+        "Input: <input for the tool>\n\n"
+        "Wait for the tool result before continuing.\n"
+        "When you know the final answer, reply with the answer **only**.\n"
+        "Don't include any prefix, explanation or formatting around the answer.\n"
+        "Answer formatting:\n"
+        "- For numbers: no units unless requested\n"
+        "- For strings: no articles or abbreviations\n"
+        "- For lists: comma + space separated, correct order\n"
     )
 )
 
 # ---------------------------------------------------------------------
 # 7) LangGraph – Planner + Tools + Router
 # ---------------------------------------------------------------------
+def extract_tool_call(text: str) -> tuple[str, str] | None:
+    """Parse Gemini output like: 'Tool: xyz\nInput: abc'."""
+    match = re.search(r"Tool:\s*(\w+)\s*Input:\s*(.+)", text, re.DOTALL)
+    if match:
+        return match.group(1).strip(), match.group(2).strip()
+    return None
+
 def planner(state: MessagesState):
-    """LLM-Planner – entscheidet, ob Tool nötig oder Final Answer erreicht."""
     msgs = state["messages"]
     if msgs[0].type != "system":
         msgs = [SYSTEM_PROMPT] + msgs
+
     resp = with_backoff(lambda: gemini_llm.invoke(msgs))
-    finished = (
-        not getattr(resp, "tool_calls", None)  # keine Toolaufrufe
-        and "\n" not in resp.content          # heuristik: kurze Endantwort
-    )
-    return {"messages": [resp], "should_end": finished}
+    content = resp.content.strip()
+
+    parsed = extract_tool_call(content)
+    if parsed:
+        tool_name, tool_input = parsed
+        tool = {t.name: t for t in TOOLS}.get(tool_name)
+        if tool:
+            result = tool.invoke(tool_input)
+            new_msg = HumanMessage(content=f"Tool result:\n{result}")
+            return {"messages": msgs + [resp, new_msg], "should_end": False}
+
+    finished = "\n" not in content  # einfache Heuristik
+    return {"messages": msgs + [resp], "should_end": finished}
 
 def route(state):
     return "END" if state["should_end"] else "tools"