Split a nightly Snowflake load with an agent

Every night your team loads the previous day's app events from an S3 export into Snowflake, in analytics.events_daily. Finance and 3 product teams build reports on it. The current job is a pile of scripts. You want an AI agent to rebuild it: read the files, remove duplicate events, add account details and load the table.

Which parts do you hand the agent, which do you keep, and where does a person check the work before a night's data goes live?