fix: correct get_device_state endpoint to use device UUID not userId

Critical fix for tool 10:
- Renamed: get_device_states → get_device_state (singular)
- Fixed endpoint: /state/devId/{deviceUuid} not /state/devId/{userId}
- Tool now gets state of ONE specific device by UUID
- Input changed from {} to {uuid: string}

We have 2 separate APIs for single device state:
1. /state/devId/{deviceUuid} - Get by device UUID (tool 10)
2. /state/{locationUuid}/{macAddress} - Get by MAC address (tool 12)

And 1 API for multiple devices:
3. /state/{locationUuid} - Get all devices in location (tool 11)

Updated TOOLS.md documentation to reflect correct usage.

Author: dadadadas111

docs/TOOLS.md

@@ -265,36 +265,40 @@ Delete a device permanently. **Cannot be undone.**
 
 ## Device State (3 tools)
 
-### 10. get_device_states
+### 10. get_device_state
 
-Get current states of ALL devices in the system.
+Get current state of a specific device by UUID.
 
 **Input:**
 
 ```json
-{}
+{
+  "uuid": "abc-123"
+}
 ```
 
 **Output:**
 
 ```json
-[
-  {
-    "uuid": "abc-123",
-    "mac": "AA:BB:CC:DD:EE:FF",
-    "loc": "location-id",
-    "devId": "device-id",
-    "state": {
-      "deviceId": {
-        "elementId": {
-          "1": [1, 1], // ON_OFF: ON
-          "28": [28, 700] // BRIGHTNESS: 700
-        }
+{
+  "uuid": "abc-123",
+  "mac": "AA:BB:CC:DD:EE:FF",
+  "loc": "location-id",
+  "devId": "device-id",
+  "state": {
+    "deviceId": {
+      "1": {
+        "1": [1, 1], // Element 1: ON_OFF: ON
+        "31": [31, 0, 0, 0] // Element 1: COLOR_HSV
+      },
+      "2": {
+        "1": [1, 1], // Element 2: ON_OFF: ON
+        "28": [28, 700] // Element 2: BRIGHTNESS: 700
       }
-    },
-    "updatedAt": "2026-02-12T10:00:00Z"
-  }
-]
+    }
+  },
+  "updatedAt": "2026-02-12T10:00:00Z"
+}
 ```
 
 **State Structure:**
@@ -310,11 +314,28 @@ Get states of all devices in a specific location.
 
 ```json
 {
-  "locationUuid": "loc-123" // Use _id from list_locations
+  "locationUuid": "loc-123" // Use uuid from list_locations
 }
 ```
 
-**Output:** Same structure as `get_device_states` but filtered by location.
+**Output:** Array of device state objects (same structure as `get_device_state`).
+
+```json
+[
+  {
+    "uuid": "abc-123",
+    "mac": "AA:BB:CC:DD:EE:FF",
+    "loc": "location-id",
+    "state": {...}
+  },
+  {
+    "uuid": "def-456",
+    "mac": "11:22:33:44:55:66",
+    "loc": "location-id",
+    "state": {...}
+  }
+]
+```
 
 ### 12. get_device_state_by_mac
 
@@ -504,7 +525,7 @@ Common device attributes (from `device-attr-and-control.csv`):
 {"tool": "control_device_simple", "uuid": "abc-123", "action": "set_brightness", "value": 700}
 
 // Step 4: Check state (wait 2-3 seconds)
-{"tool": "get_device_states"}
+{"tool": "get_device_state", "uuid": "abc-123"}
 ```
 
 ### Example 3: Control Air Conditioner
@@ -604,9 +625,9 @@ The control API only publishes MQTT messages - it doesn't guarantee device state
 
 ### State Endpoints
 
-- `GET /iot-core/state/devId/{devId}` - All device states
-- `GET /iot-core/state/{locationUuid}` - States by location
-- `GET /iot-core/state/{locationUuid}/{macAddress}` - State by MAC
+- `GET /iot-core/state/devId/{deviceUuid}` - Single device state by UUID
+- `GET /iot-core/state/{locationUuid}` - All device states in a location
+- `GET /iot-core/state/{locationUuid}/{macAddress}` - Single device state by MAC address
 
 ### Control Endpoint
 

src/mcp/services/mcp.service.ts

@@ -843,15 +843,17 @@ export class McpService {
       },
     );
 
-    // Tool 10: get_device_states - Get states for all devices
+    // Tool 10: get_device_state - Get state of a single device by UUID
     server.registerTool(
-      'get_device_states',
+      'get_device_state',
       {
         description:
-          'Get current states of all IoT devices. Returns state information including attributes, values, and last update times for all devices in the system.',
-        inputSchema: z.object({}),
+          'Get current state of a specific IoT device by its UUID. Returns state information including attributes, values, and last update time for the device.',
+        inputSchema: z.object({
+          uuid: z.string().describe('Device UUID (unique identifier)'),
+        }),
       },
-      async (_, extra) => {
+      async ({ uuid }, extra) => {
         const sessionKey = extra?.sessionId || 'default';
         const connectionState = this.connectionStates.get(sessionKey);
 
@@ -860,29 +862,26 @@ export class McpService {
         }
 
         try {
-          this.logger.debug(`[get_device_states] Fetching all device states`);
-          const states = await this.apiClient.get(
-            `/state/devId/${connectionState.userId}`,
-            connectionState.token,
-          );
+          this.logger.debug(`[get_device_state] Fetching state for device: ${uuid}`);
+          const state = await this.apiClient.get(`/state/devId/${uuid}`, connectionState.token);
 
-          this.logger.log(`[get_device_states] Retrieved states successfully`);
+          this.logger.log(`[get_device_state] Retrieved device state successfully`);
 
           return {
             content: [
               {
                 type: 'text' as const,
-                text: JSON.stringify(states, null, 2),
+                text: JSON.stringify(state, null, 2),
               },
             ],
           };
         } catch (error) {
-          this.logger.error('[get_device_states] Failed:', error);
+          this.logger.error('[get_device_state] Failed:', error);
           return {
             content: [
               {
                 type: 'text' as const,
-                text: `Failed to get device states: ${error.message}`,
+                text: `Failed to get device state: ${error.message}`,
               },
             ],
             isError: true,
@@ -1304,7 +1303,7 @@ export class McpService {
     );
 
     this.logger.log(
-      'MCP tools registered successfully: login, search, fetch, list_devices, list_locations, list_groups, get_device, update_device, delete_device, get_device_states, get_location_state, get_device_state_by_mac, control_device, control_device_simple',
+      'MCP tools registered successfully: login, search, fetch, list_devices, list_locations, list_groups, get_device, update_device, delete_device, get_device_state, get_location_state, get_device_state_by_mac, control_device, control_device_simple',
     );
   }
 }