Gemini 3 Reflection Prompt Before Each Tool Call

To improve agentic tool accuracy in Gemini 3, enforce a Pre-Computation Reflection rule requiring the model to explicitly state three things before calling any tool.

<pre_tool_reflection>
Before calling any tool, you must explicitly state:
1. Why you are calling the tool.
2. What specific data you expect to retrieve.
3. How that data helps solve the user's problem.
</pre_tool_reflection>