**Setup:** Guides the user through one-time Google Cloud OAuth client setup, enabling Gmail and People APIs, and configuring OAuth consent.
**Authentication:** Authenticates with the specified Gmail account using OAuth 2.0.
**Command Execution:** Executes the requested Gmail command (e.g., search, read, send, draft) using the Gmail API.
**Data Processing:** Processes the data returned from the Gmail API, formatting it for user readability.
**Confirmation (Send Email):** If sending an email, presents the email details to the user for explicit confirmation before sending.
**Output:** Returns the results in JSON format.