Fix empty tool-use response handling

s04_hooks/README.ja.md

@@ -130,7 +130,7 @@ register_hook("PreToolUse", log_hook)
 register_hook("PostToolUse", large_output_hook)
 ```
 
-**Stop** はループが終了する直前に発火する（`stop_reason != "tool_use"`）。以下の hook は終了時の統計を出力する：
+**Stop** はループが終了する直前に発火する。以下の hook は終了時の統計を出力する：
 
 ```python
 def summary_hook(messages: list) -> str | None:
@@ -147,7 +147,10 @@ register_hook("Stop", summary_hook)
 agent_loop 内では、終了前に発火：
 
 ```python
-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)   # ← 終了する前に
     if force:
         # フックがメッセージを返した → 注入して続行
@@ -159,10 +162,7 @@ if response.stop_reason != "tool_use":
 **ループ内で変更されたのは一箇所だけ**：s03 は直接 `check_permission(block)` を呼び出していたが、s04 は `trigger_hooks("PreToolUse", block)` に置き換えた：
 
 ```python
-for block in response.content:
-    if block.type != "tool_use":
-        continue
-
+for block in tool_calls:
     # s03: if not check_permission(block): ...
     # s04: フックがハードコードを代替
     blocked = trigger_hooks("PreToolUse", block)

s04_hooks/README.md

@@ -130,7 +130,7 @@ register_hook("PreToolUse", log_hook)
 register_hook("PostToolUse", large_output_hook)
 ```
 
-**Stop** triggers when the loop is about to exit (`stop_reason != "tool_use"`). The following hook prints a cleanup summary:
+**Stop** triggers when the loop is about to exit. The following hook prints a cleanup summary:
 
 ```python
 def summary_hook(messages: list) -> str | None:
@@ -147,7 +147,10 @@ register_hook("Stop", summary_hook)
 In agent_loop, triggered before exit:
 
 ```python
-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)   # ← before exiting
     if force:
         # hook returned a message → inject it and continue
@@ -159,10 +162,7 @@ if response.stop_reason != "tool_use":
 **Only one change in the loop**: s03 directly called `check_permission(block)`, s04 replaces it with `trigger_hooks("PreToolUse", block)`:
 
 ```python
-for block in response.content:
-    if block.type != "tool_use":
-        continue
-
+for block in tool_calls:
     # s03: if not check_permission(block): ...
     # s04: hooks replace hardcoding
     blocked = trigger_hooks("PreToolUse", block)

s04_hooks/README.zh.md

@@ -130,7 +130,7 @@ register_hook("PreToolUse", log_hook)
 register_hook("PostToolUse", large_output_hook)
 ```
 
-**Stop** 在循环即将退出时触发（`stop_reason != "tool_use"`）。以下 hook 打印收尾统计：
+**Stop** 在循环即将退出时触发。以下 hook 打印收尾统计：
 
 ```python
 def summary_hook(messages: list) -> str | None:
@@ -147,7 +147,10 @@ register_hook("Stop", summary_hook)
 在 agent_loop 中，退出前触发：
 
 ```python
-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)   # ← 退出之前
     if force:
         # hook returned a message → inject it and continue
@@ -159,10 +162,7 @@ if response.stop_reason != "tool_use":
 **循环里只改了一处**：s03 直接调用 `check_permission(block)`，s04 改为 `trigger_hooks("PreToolUse", block)`：
 
 ```python
-for block in response.content:
-    if block.type != "tool_use":
-        continue
-
+for block in tool_calls:
     # s03: if not check_permission(block): ...
     # s04: hook 替代硬编码
     blocked = trigger_hooks("PreToolUse", block)

s04_hooks/code.py

@@ -205,7 +205,10 @@ 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})
@@ -213,10 +216,7 @@ def agent_loop(messages: list):
             return
 
         results = []
-        for block in response.content:
-            if block.type != "tool_use":
-                continue
-
+        for block in tool_calls:
             # s04 change: hook replaces hard-coded check_permission()
             blocked = trigger_hooks("PreToolUse", block)
             if blocked:

s04_hooks/images/hooks-overview.en.svg

@@ -39,7 +39,7 @@
   <!-- ② LLM -->
   <rect x="200" y="108" width="120" height="64" rx="8" fill="#fff" stroke="#2563eb" stroke-width="1.5"/>
   <text x="260" y="134" fill="#1e3a5f" font-size="14" font-weight="700" text-anchor="middle">LLM</text>
-  <text x="260" y="154" fill="#64748b" font-size="10" text-anchor="middle">stop_reason=tool_use?</text>
+  <text x="260" y="154" fill="#64748b" font-size="10" text-anchor="middle">tool_use block?</text>
 
   <!-- LLM No → Return -->
   <line x1="260" y1="172" x2="260" y2="200" stroke="#16a34a" stroke-width="2" marker-end="url(#arrow)"/>

s04_hooks/images/hooks-overview.ja.svg

@@ -39,7 +39,7 @@
   <!-- ② LLM -->
   <rect x="200" y="108" width="120" height="64" rx="8" fill="#fff" stroke="#2563eb" stroke-width="1.5"/>
   <text x="260" y="134" fill="#1e3a5f" font-size="14" font-weight="700" text-anchor="middle">LLM</text>
-  <text x="260" y="154" fill="#64748b" font-size="10" text-anchor="middle">stop_reason=tool_use?</text>
+  <text x="260" y="154" fill="#64748b" font-size="10" text-anchor="middle">tool_use block?</text>
 
   <!-- LLM No → 返却 -->
   <line x1="260" y1="172" x2="260" y2="200" stroke="#16a34a" stroke-width="2" marker-end="url(#arrow)"/>

s04_hooks/images/hooks-overview.svg

@@ -39,7 +39,7 @@
   <!-- ② LLM -->
   <rect x="200" y="108" width="120" height="64" rx="8" fill="#fff" stroke="#2563eb" stroke-width="1.5"/>
   <text x="260" y="134" fill="#1e3a5f" font-size="14" font-weight="700" text-anchor="middle">LLM</text>
-  <text x="260" y="154" fill="#64748b" font-size="10" text-anchor="middle">stop_reason=tool_use?</text>
+  <text x="260" y="154" fill="#64748b" font-size="10" text-anchor="middle">tool_use block?</text>
 
   <!-- LLM 否 → 返回 -->
   <line x1="260" y1="172" x2="260" y2="200" stroke="#16a34a" stroke-width="2" marker-end="url(#arrow)"/>