refactor: break up should_use_tools into helpers (#624)

Co-authored-by: Kimi Agent <kimi@timmy.local>
Co-committed-by: Kimi Agent <kimi@timmy.local>

src/timmy/conversation.py

@@ -174,15 +174,8 @@ class ConversationManager:
 
         return None
 
-    def should_use_tools(self, message: str, context: ConversationContext) -> bool:
-        """Determine if this message likely requires tools.
-
-        Returns True if tools are likely needed, False for simple chat.
-        """
-        message_lower = message.lower().strip()
-
-        # Tool keywords that suggest tool usage is needed
-        tool_keywords = [
+    _TOOL_KEYWORDS = frozenset(
+        {
             "search",
             "look up",
             "find",
@@ -203,10 +196,11 @@ class ConversationManager:
             "shell",
             "command",
             "install",
-        ]
+        }
+    )
 
-        # Chat-only keywords that definitely don't need tools
-        chat_only = [
+    _CHAT_ONLY_KEYWORDS = frozenset(
+        {
             "hello",
             "hi ",
             "hey",
@@ -221,30 +215,47 @@ class ConversationManager:
             "goodbye",
             "tell me about yourself",
             "what can you do",
-        ]
+        }
+    )
 
-        # Check for chat-only patterns first
-        for pattern in chat_only:
-            if pattern in message_lower:
-                return False
+    _SIMPLE_QUESTION_PREFIXES = ("what is", "who is", "how does", "why is", "when did", "where is")
+    _TIME_WORDS = ("today", "now", "current", "latest", "this week", "this month")
 
-        # Check for tool keywords
-        for keyword in tool_keywords:
-            if keyword in message_lower:
-                return True
+    def _is_chat_only(self, message_lower: str) -> bool:
+        """Return True if the message matches a chat-only pattern."""
+        return any(kw in message_lower for kw in self._CHAT_ONLY_KEYWORDS)
 
-        # Simple questions (starting with what, who, how, why, when, where)
-        # usually don't need tools unless about current/real-time info
-        simple_question_words = ["what is", "who is", "how does", "why is", "when did", "where is"]
-        for word in simple_question_words:
-            if message_lower.startswith(word):
-                # Check if it's asking about current/real-time info
-                time_words = ["today", "now", "current", "latest", "this week", "this month"]
-                if any(t in message_lower for t in time_words):
-                    return True
-                return False
+    def _has_tool_keyword(self, message_lower: str) -> bool:
+        """Return True if the message contains a tool-related keyword."""
+        return any(kw in message_lower for kw in self._TOOL_KEYWORDS)
+
+    def _is_simple_question(self, message_lower: str) -> bool | None:
+        """Check if message is a simple question.
+
+        Returns True if it needs tools (real-time info), False if it
+        doesn't, or None if the message isn't a simple question.
+        """
+        for prefix in self._SIMPLE_QUESTION_PREFIXES:
+            if message_lower.startswith(prefix):
+                return any(t in message_lower for t in self._TIME_WORDS)
+        return None
+
+    def should_use_tools(self, message: str, context: ConversationContext) -> bool:
+        """Determine if this message likely requires tools.
+
+        Returns True if tools are likely needed, False for simple chat.
+        """
+        message_lower = message.lower().strip()
+
+        if self._is_chat_only(message_lower):
+            return False
+        if self._has_tool_keyword(message_lower):
+            return True
+
+        simple = self._is_simple_question(message_lower)
+        if simple is not None:
+            return simple
 
-        # Default: don't use tools for unclear cases
         return False