adk web bug

new start with google adk, when run ``adk run web`` , get the error

code
```
root_agent = LlmAgent(
name="weather_time_agent",
model=LiteLlm(model="deepseek/deepseek-chat"),
description=(
"Agent to answer questions about the time and weather in a city."
),
instruction=(
"You are a helpful agent who can answer user questions about the time and weather in a city."
),
tools=[get_weather, get_current_time],
)
```