fix: disable preemptive_generation for tool call compatibility; add get_time tool

- preemptive_generation was incompatible with MCP tool calls: it starts
  generating before the turn finalizes, breaking the tool execution loop
  (agent said 'let me check' then hung forever)
- Add get_time(location?) to weather_mcp.py for date/time queries
- Update system prompt with Weather & Time section

Dockerfile

@@ -41,6 +41,7 @@ RUN curl -sSL "https://github.com/livekit/livekit/releases/download/${LIVEKIT_VE
 COPY --from=build /app/agent/.venv /opt/voice-agent/.venv
 COPY agent/agent.py /opt/voice-agent/agent.py
 COPY agent/web_mcp.py /opt/voice-agent/web_mcp.py
+COPY agent/weather_mcp.py /opt/voice-agent/weather_mcp.py
 
 # Copy web frontend + token endpoint
 COPY web/index.html /var/www/voice/

agent/agent.py

@@ -70,10 +70,12 @@ SYSTEM_PROMPT = textwrap.dedent("""\
     source naturally ("according to..."). If a search comes up empty, say so
     briefly and move on.
 
-    # Weather
+    # Weather & Time
     You can check the weather for any location. Use get_weather when the user
     asks about current conditions, temperature, or forecasts. It returns a
     short summary — relay it naturally in your own words.
+    Use get_time when the user asks what time or day it is. If they mention
+    a city, pass it as the location argument.
 """)
 
 
@@ -269,8 +271,9 @@ async def handle_job(ctx: JobContext) -> None:
             # VAD-based turn detection: agent waits for user to stop speaking.
             # ("adaptive" mode requires the LiveKit Cloud barge-in service.)
             interruption={"mode": "vad"},
-            # Start generating the LLM response before the user fully stops
+            # Preemptive generation is incompatible with tool calls — it starts
-            preemptive_generation={"enabled": True},
+            # generating before the turn finalizes, breaking the MCP execution loop.
+            preemptive_generation={"enabled": False},
         ),
     )
 

agent/weather_mcp.py

@@ -14,6 +14,7 @@ The tool returns a short, conversational summary suitable for speech
 from __future__ import annotations
 
 import os
+from datetime import datetime, timezone
 
 import httpx
 from mcp.server.fastmcp import FastMCP
@@ -84,5 +85,43 @@ async def get_weather(location: str) -> str:
     return summary
 
 
+@mcp.tool()
+def get_time(location: str = "") -> str:
+    """Get the current date and time.
+
+    If a location is provided, returns the local time there (approximated
+    via wttr.in's timezone data). Otherwise returns UTC time.
+    Use this when the user asks what time or day it is.
+    """
+    if not location:
+        now = datetime.now(timezone.utc)
+        return f"It's {now.strftime('%I:%M %p')} on {now.strftime('%A, %B %d')}, UTC."
+
+    try:
+        async def _fetch():
+            async with httpx.AsyncClient(timeout=15) as client:
+                resp = await client.get(
+                    f"{WTTR_BASE}/{location}?format=j1",
+                    headers={"User-Agent": "curl/8.0"},
+                )
+                resp.raise_for_status()
+                return resp.json()
+
+        import asyncio
+        data = asyncio.get_event_loop().run_until_complete(_fetch())
+        current = data.get("current_condition", [{}])[0] or {}
+        tz_offset = current.get("localObsDateTime", "")
+        area = data.get("nearest_area", [{}])[0] or {}
+        city = (area.get("areaName", [{}])[0].get("value") or location).strip()
+
+        if tz_offset:
+            return f"It's {tz_offset.split(' ')[1][:5]} on {tz_offset.split(' ')[0]} in {city}."
+    except Exception:  # noqa: BLE001
+        pass
+
+    now = datetime.now(timezone.utc)
+    return f"It's {now.strftime('%I:%M %p')} on {now.strftime('%A, %B %d')}, UTC."
+
+
 if __name__ == "__main__":
     mcp.run(transport="stdio")