Integrate Graphite for Observability

Modify your Google ADK agent to send detailed traces and logs to Graphite for every tool call, LLM interaction, and decision point. Ensure that privacy-sensitive information is masked or omitted from logs. Your implementation should demonstrate how Graphite helps in debugging the agent's reasoning process and verifying data access decisions. 

```python
# from google_adk.tools import Tool
# from graphite import Client

# graphite_client = Client(api_key="YOUR_GRAPHITE_API_KEY")

# class TracedGmailReader(SimulatedGmailReader):
#    def call(self, user_id: str, consent_level: dict):
#        graphite_client.log_event("Gmail_Tool_Call_Start", {"user_id": user_id, "requested_access": "email"})
#        response = super().call(user_id, consent_level)
#        graphite_client.log_event("Gmail_Tool_Call_End", {"user_id": user_id, "response_status": "success" if "Access denied" not in response else "denied"})
#        return response

# (Then use TracedGmailReader in your agent)
```