Update code for tool call

engine/docs/ws_v1_schema.md

@@ -110,6 +110,24 @@ Rules:
 }
 ```
 
+### `tool_call.results`
+
+Client tool execution results returned to server.
+
+```json
+{
+  "type": "tool_call.results",
+  "results": [
+    {
+      "tool_call_id": "call_abc123",
+      "name": "weather",
+      "output": { "temp_c": 21, "condition": "sunny" },
+      "status": { "code": 200, "message": "ok" }
+    }
+  ]
+}
+```
+
 ## Server -> Client Events
 
 All server events include:
@@ -142,6 +160,8 @@ Common events:
   - Fields: `trackId`, `text`
 - `assistant.response.final`
   - Fields: `trackId`, `text`
+- `assistant.tool_call`
+  - Fields: `trackId`, `tool_call`
 - `output.audio.start`
   - Fields: `trackId`
 - `output.audio.end`