refine agent subscription defaults and silent tool prompts

tests/test_agent_add_subscribe_tool.py

@@ -0,0 +1,29 @@
+import asyncio
+import unittest
+from unittest.mock import AsyncMock, patch
+
+from app.agent.tools.impl.add_subscribe import AddSubscribeTool
+
+
+class TestAgentAddSubscribeTool(unittest.TestCase):
+    def test_tv_subscription_without_season_reports_default_first_season(self):
+        tool = AddSubscribeTool(session_id="session-1", user_id="10001")
+
+        with patch(
+            "app.agent.tools.impl.add_subscribe.SubscribeChain.async_add",
+            new=AsyncMock(return_value=(1, "")),
+        ):
+            result = asyncio.run(
+                tool.run(
+                    title="Breaking Bad",
+                    year="2008",
+                    media_type="tv",
+                )
+            )
+
+        self.assertIn("第1季", result)
+        self.assertIn("默认按第一季订阅", result)
+
+
+if __name__ == "__main__":
+    unittest.main()