Split a caching ticket into checked agent steps

You picked up a ticket that says only "Add caching to the public API". You want an AI agent to do the work, but the ticket is too vague for one prompt.

The service is a Go HTTP server that runs as 3 replicas behind a load balancer. Each API key belongs to one customer account, and most endpoints return that account's data. Customers also change their data through the same API.

How do you break it into agent-sized steps, and what do you check before the agent moves on from each?