feat: optimize Housekeeper for Mistral-Nemo tool calling

- Rewrite system prompt with negative constraints and step-by-step process
- Set temperature to 0.1 for deterministic tool calling
- Sort room groups to top of device list (address positional bias)
- Add [ROOM GROUP] marker in list_devices output
- Update tool docstrings with explicit entity_id= parameter examples
- Add optimization findings doc (experiment log: 0% → 100% success)
- Add test script for room group detection regression testing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/agents/housekeeper/tools.py

@@ -59,10 +59,27 @@ async def list_devices(
 
             for dom, dom_devices in sorted(by_domain.items()):
                 output_parts.append(f"### {dom.title()}s")
-                for device in dom_devices:
+
+                # Sort devices: room groups first (using Home Assistant's is_hue_group attribute)
+                def is_room_group(d: object) -> bool:
+                    """Check if device is a room group based on HA attributes."""
+                    attrs = getattr(d, "attributes", {})
+                    # Check for Hue room groups
+                    if attrs.get("is_hue_group") and attrs.get("hue_type") == "room":
+                        return True
+                    # Check for other group indicators (icon or entity_id list)
+                    if "entity_id" in attrs and isinstance(attrs["entity_id"], list):
+                        return True
+                    return False
+
+                sorted_devices = sorted(dom_devices, key=lambda d: (not is_room_group(d), d.entity_id))
+
+                for device in sorted_devices:
                     state_icon = "on" if device.state == "on" else "off" if device.state == "off" else device.state
                     area_str = f" ({device.area})" if device.area else ""
-                    output_parts.append(f"- **{device.name}**{area_str}: {state_icon}")
+                    # Mark room groups clearly using actual HA data
+                    group_marker = " [ROOM GROUP]" if is_room_group(device) else ""
+                    output_parts.append(f"- **{device.name}**{area_str}{group_marker}: {state_icon}")
                     output_parts.append(f"  ID: `{device.entity_id}`")
                 output_parts.append("")
 
@@ -164,12 +181,12 @@ async def turn_on(
     color_temp: int | None = None,
 ) -> str:
     """
-    Turn on a device.
+    Turn on a device. Use the entity_id parameter with the EXACT value from list_devices.
 
     For lights, can optionally set brightness and color temperature.
 
     Args:
-        entity_id: Device to turn on (e.g., light.living_room, switch.coffee_maker)
+        entity_id: The EXACT entity ID from list_devices including domain prefix.
         brightness: Optional brightness for lights (0-255, where 255 is full brightness)
         color_temp: Optional color temperature in Kelvin (2700=warm, 6500=cool)
 
@@ -177,10 +194,9 @@ async def turn_on(
         Confirmation of the action
 
     Examples:
-        turn_on("light.living_room")  # Turn on at current brightness
-        turn_on("light.bedroom", brightness=128)  # Turn on at 50% brightness
-        turn_on("light.office", brightness=255, color_temp=4000)  # Full, neutral white
-        turn_on("switch.coffee_maker")  # Turn on a switch
+        turn_on(entity_id="light.living_room")
+        turn_on(entity_id="light.bedroom", brightness=128)
+        turn_on(entity_id="switch.coffee_maker")
     """
     try:
         async with CoreAPIClient() as client:
@@ -209,17 +225,18 @@ async def turn_on(
 
 async def turn_off(entity_id: str) -> str:
     """
-    Turn off a device.
+    Turn off a device. Use the entity_id parameter with the EXACT value from list_devices.
 
     Args:
-        entity_id: Device to turn off (e.g., light.living_room, switch.coffee_maker)
+        entity_id: The EXACT entity ID from list_devices including domain prefix.
 
     Returns:
         Confirmation of the action
 
     Examples:
-        turn_off("light.living_room")
-        turn_off("switch.coffee_maker")
+        turn_off(entity_id="light.living_room")
+        turn_off(entity_id="switch.coffee_maker")
+        turn_off(entity_id="light.kitchen")
     """
     try:
         async with CoreAPIClient() as client:
@@ -239,15 +256,17 @@ async def toggle(entity_id: str) -> str:
     """
     Toggle a device's state (on becomes off, off becomes on).
 
+    Use the entity_id parameter with the EXACT value from list_devices.
+
     Args:
-        entity_id: Device to toggle
+        entity_id: The EXACT entity ID from list_devices including domain prefix.
 
     Returns:
         Confirmation with the new state
 
     Examples:
-        toggle("light.living_room")
-        toggle("switch.fan")
+        toggle(entity_id="light.living_room")
+        toggle(entity_id="switch.fan")
     """
     try:
         async with CoreAPIClient() as client: