fix: migliora parsing e system prompt per tool calling

- Nuovo formato TOOL:toolname|arg=val più semplice
- System prompt semplificato con lista chiara tool
- Parsing supporta sia formato nuovo che vecchio
- Validazione tool names esistenti

ollama_agent.py

@@ -21,7 +21,12 @@ from langchain_core.tools import Tool
 # TOOL CALL PATTERNS
 # =============================================================================
 
-TOOL_CALL_PATTERN = r'\[TOOL_CALL\]\s*(.*?)\s*\[\/TOOL_CALL\]'
+# Old format: [TOOL_CALL]...[/TOOL_CALL]
+TOOL_CALL_PATTERN_OLD = r'\[TOOL_CALL\]\s*(.*?)\s*\[\/TOOL_CALL\]'
+
+# New format: TOOL:toolname|arg1=val1|arg2=val2
+TOOL_CALL_PATTERN_NEW = r'^TOOL:(\w+)(?:\|(.*))?$'
+
 TOOL_RESULT_PATTERN = r'\[TOOL_RESULT\]\s*(.*?)\s*\[\/TOOL_RESULT\]'
 
 
@@ -227,17 +232,29 @@ class OllamaToolAgent:
         
     def _default_system_prompt(self) -> str:
         """System prompt di default"""
-        return """You are LangCode, a helpful AI assistant with access to tools.
+        return """You are LangCode AI. You have access to these tools:
 
-When you need to use a tool, you MUST respond with this EXACT format:
+1. system_info - Get system info (OS, Python version, etc). No arguments needed.
+2. ls(path=".") - List directory contents. Use path="." for current directory.
+3. execute(command) - Run shell commands. Example: execute("ls -la")
+4. read_file(path) - Read file contents. Example: read_file("/path/to/file")
+5. write_file(path, content) - Write to file.
+6. search(directory, pattern) - Search for files. Example: search(".", "*.py")
 
-[TOOL_CALL]
-{"tool": "tool_name", "arguments": {"arg1": "value1", "arg2": "value2"}}
-[/TOOL_CALL]
+IMPORTANT RULES:
+- ONLY use these exact tool names: system_info, ls, execute, read_file, write_file, search
+- NEVER invent tool names
+- When you need a tool, output ONLY this format (no other text):
 
-After receiving the tool result, continue your response normally.
+TOOL:system_info
+TOOL:ls|path=.
+TOOL:execute|command=ls -la
+TOOL:read_file|path=/path/to/file
+TOOL:write_file|path=/file.txt|content=hello
+TOOL:search|directory=.|pattern=*.py
 
-Available tools:"""
+- After the tool result, you can respond normally.
+- If no tool is needed, just respond normally."""
     
     def _tool_instructions(self) -> str:
         """Genera le istruzioni per i tool disponibili"""
@@ -286,17 +303,45 @@ Available tools:"""
     def _parse_tool_calls(self, text: str) -> List[ToolCall]:
         """Parse le chiamate tool dalla risposta del modello"""
         tool_calls = []
-        matches = re.finditer(TOOL_CALL_PATTERN, text, re.DOTALL)
         
+        # Try new format first: TOOL:toolname|arg1=val1
+        lines = text.strip().split('\n')
+        for line in lines:
+            line = line.strip()
+            if line.startswith('TOOL:'):
+                # Parse: TOOL:toolname|arg1=val1|arg2=val2
+                match = re.match(r'^TOOL:(\w+)(?:\|(.+))?$', line)
+                if match:
+                    tool_name = match.group(1)
+                    if tool_name in self.tools:
+                        args = {}
+                        if match.group(2):
+                            # Parse arguments: arg1=val1|arg2=val2
+                            for arg_part in match.group(2).split('|'):
+                                if '=' in arg_part:
+                                    key, val = arg_part.split('=', 1)
+                                    args[key] = val
+                        tool_calls.append(ToolCall(
+                            id=str(uuid.uuid4())[:8],
+                            name=tool_name,
+                            arguments=args
+                        ))
+                        # If we found a valid tool call, return only that one
+                        return tool_calls
+        
+        # Try old format: [TOOL_CALL]{...}[/TOOL_CALL]
+        matches = re.finditer(TOOL_CALL_PATTERN_OLD, text, re.DOTALL)
         for match in matches:
             try:
                 data = json.loads(match.group(1))
-                tool_calls.append(ToolCall(
-                    id=str(uuid.uuid4())[:8],
-                    name=data.get('tool'),
-                    arguments=data.get('arguments', {})
-                ))
-            except json.JSONDecodeError:
+                tool_name = data.get('tool')
+                if tool_name and tool_name in self.tools:
+                    tool_calls.append(ToolCall(
+                        id=str(uuid.uuid4())[:8],
+                        name=tool_name,
+                        arguments=data.get('arguments', {})
+                    ))
+            except (json.JSONDecodeError, TypeError):
                 continue
         
         return tool_calls
@@ -304,7 +349,11 @@ Available tools:"""
     def _execute_tool(self, tool_call: ToolCall) -> Any:
         """Esegui un singolo tool"""
         if tool_call.name not in self.tools:
-            return {"error": f"Tool '{tool_call.name}' not found"}
+            available = ", ".join(self.tools.keys())
+            return {
+                "error": f"Tool '{tool_call.name}' not found",
+                "available_tools": available
+            }
         
         try:
             tool = self.tools[tool_call.name]