diff --git a/tests/test_tool_contextvars.py b/tests/test_tool_contextvars.py
index 3cfef9515..1303f0001 100644
--- a/tests/test_tool_contextvars.py
+++ b/tests/test_tool_contextvars.py
@@ -101,3 +101,99 @@ async def test_cron_tool_keeps_task_local_context(tmp_path) -> None:
     jobs = tool._cron.list_jobs()
     assert {job.payload.channel for job in jobs} == {"feishu", "email"}
     assert {job.payload.to for job in jobs} == {"chat-a", "chat-b"}
+
+
+# --- Basic single-task regression tests ---
+
+
+@pytest.mark.asyncio
+async def test_message_tool_basic_set_context_and_execute() -> None:
+    """Single task: set_context then execute should route correctly."""
+    seen: list[tuple[str, str, str]] = []
+
+    async def send_callback(msg):
+        seen.append((msg.channel, msg.chat_id, msg.content))
+
+    tool = MessageTool(send_callback=send_callback)
+    tool.set_context("telegram", "chat-123", "msg-456")
+
+    result = await tool.execute(content="hello")
+    assert result == "Message sent to telegram:chat-123"
+    assert seen == [("telegram", "chat-123", "hello")]
+
+
+@pytest.mark.asyncio
+async def test_message_tool_default_values_without_set_context() -> None:
+    """Without set_context, constructor defaults should be used."""
+    seen: list[tuple[str, str, str]] = []
+
+    async def send_callback(msg):
+        seen.append((msg.channel, msg.chat_id, msg.content))
+
+    tool = MessageTool(
+        send_callback=send_callback,
+        default_channel="discord",
+        default_chat_id="general",
+    )
+
+    result = await tool.execute(content="hi")
+    assert result == "Message sent to discord:general"
+    assert seen == [("discord", "general", "hi")]
+
+
+@pytest.mark.asyncio
+async def test_spawn_tool_basic_set_context_and_execute() -> None:
+    """Single task: set_context then execute should pass correct origin."""
+    seen: list[tuple[str, str, str]] = []
+
+    class _Manager:
+        async def spawn(self, *, task, label, origin_channel, origin_chat_id, session_key):
+            seen.append((origin_channel, origin_chat_id, session_key))
+            return f"ok: {task}"
+
+    tool = SpawnTool(_Manager())
+    tool.set_context("feishu", "chat-abc")
+
+    result = await tool.execute(task="do something")
+    assert result == "ok: do something"
+    assert seen == [("feishu", "chat-abc", "feishu:chat-abc")]
+
+
+@pytest.mark.asyncio
+async def test_spawn_tool_default_values_without_set_context() -> None:
+    """Without set_context, default cli:direct should be used."""
+    seen: list[tuple[str, str, str]] = []
+
+    class _Manager:
+        async def spawn(self, *, task, label, origin_channel, origin_chat_id, session_key):
+            seen.append((origin_channel, origin_chat_id, session_key))
+            return "ok"
+
+    tool = SpawnTool(_Manager())
+
+    await tool.execute(task="test")
+    assert seen == [("cli", "direct", "cli:direct")]
+
+
+@pytest.mark.asyncio
+async def test_cron_tool_basic_set_context_and_execute(tmp_path) -> None:
+    """Single task: set_context then add job should use correct target."""
+    tool = CronTool(CronService(tmp_path / "jobs.json"))
+    tool.set_context("wechat", "user-789")
+
+    result = await tool.execute(action="add", message="standup", every_seconds=300)
+    assert result.startswith("Created job")
+
+    jobs = tool._cron.list_jobs()
+    assert len(jobs) == 1
+    assert jobs[0].payload.channel == "wechat"
+    assert jobs[0].payload.to == "user-789"
+
+
+@pytest.mark.asyncio
+async def test_cron_tool_no_context_returns_error(tmp_path) -> None:
+    """Without set_context, add should fail with a clear error."""
+    tool = CronTool(CronService(tmp_path / "jobs.json"))
+
+    result = await tool.execute(action="add", message="test", every_seconds=60)
+    assert result == "Error: no session context (channel/chat_id)"