Fix empty tool-use response handling

s05_todo_write/code.py

@@ -284,7 +284,10 @@ def agent_loop(messages: list):
         )
         messages.append({"role": "assistant", "content": response.content})
 
-        if response.stop_reason != "tool_use":
+        tool_calls = [
+            block for block in response.content if block.type == "tool_use"
+        ]
+        if not tool_calls:
             force = trigger_hooks("Stop", messages)
             if force:
                 messages.append({"role": "user", "content": force})
@@ -293,10 +296,7 @@ def agent_loop(messages: list):
 
         results = []
         used_todo = False
-        for block in response.content:
-            if block.type != "tool_use":
-                continue
-
+        for block in tool_calls:
             blocked = trigger_hooks("PreToolUse", block)
             if blocked:
                 results.append({"type": "tool_result", "tool_use_id": block.id,

s05_todo_write/images/todo-overview.en.svg

@@ -36,7 +36,7 @@
   <!-- LLM -->
   <rect x="190" y="86" width="110" height="52" rx="8" fill="#fff" stroke="#2563eb" stroke-width="1.5"/>
   <text x="245" y="108" fill="#1e3a5f" font-size="13" font-weight="700" text-anchor="middle">LLM</text>
-  <text x="245" y="126" fill="#64748b" font-size="9" text-anchor="middle">stop_reason=tool_use?</text>
+  <text x="245" y="126" fill="#64748b" font-size="9" text-anchor="middle">tool_use block?</text>
 
   <!-- No → Return -->
   <line x1="245" y1="138" x2="245" y2="162" stroke="#16a34a" stroke-width="2" marker-end="url(#arrow)"/>

s05_todo_write/images/todo-overview.ja.svg

@@ -36,7 +36,7 @@
   <!-- LLM -->
   <rect x="190" y="86" width="110" height="52" rx="8" fill="#fff" stroke="#2563eb" stroke-width="1.5"/>
   <text x="245" y="108" fill="#1e3a5f" font-size="13" font-weight="700" text-anchor="middle">LLM</text>
-  <text x="245" y="126" fill="#64748b" font-size="9" text-anchor="middle">stop_reason=tool_use?</text>
+  <text x="245" y="126" fill="#64748b" font-size="9" text-anchor="middle">tool_use block?</text>
 
   <!-- No → 返却 -->
   <line x1="245" y1="138" x2="245" y2="162" stroke="#16a34a" stroke-width="2" marker-end="url(#arrow)"/>

s05_todo_write/images/todo-overview.svg

@@ -36,7 +36,7 @@
   <!-- LLM -->
   <rect x="190" y="86" width="110" height="52" rx="8" fill="#fff" stroke="#2563eb" stroke-width="1.5"/>
   <text x="245" y="108" fill="#1e3a5f" font-size="13" font-weight="700" text-anchor="middle">LLM</text>
-  <text x="245" y="126" fill="#64748b" font-size="9" text-anchor="middle">stop_reason=tool_use?</text>
+  <text x="245" y="126" fill="#64748b" font-size="9" text-anchor="middle">tool_use block?</text>
 
   <!-- 否 → 返回 -->
   <line x1="245" y1="138" x2="245" y2="162" stroke="#16a34a" stroke-width="2" marker-end="url(#arrow)"/>