Oracle: Let a Cheap Model Consult a Premium One on Demand
Oracle is a CLI and Claude Code skill for getting a second opinion from a stronger model. A lesser model drives, escalates the hard calls to a premium one, and adversarial review goes through the same door. Pay premium only for the 10% that needs it.
Oracle is the consult-a-stronger-model move packaged as a tool. A cheaper model does the bulk of the work and pings the oracle only on the hard calls (sonnet to opus, gpt-5.4-mini to gpt-5.5), so you pay premium for the 10% that actually needs it. Adversarial review and final pre-merge checks go through the same door.
In Claude Code you get two flavours: the native /advisor, and the /oracle skill, which wraps the oracle CLI with prompt and file bundling. This is the routing half of the Token Optimisation Playbook: cheap drives, premium consults.