What makes a search arbitrage ad compliant?
A compliant ad tells the truth about what the visitor will find. It describes the topic of the page, avoids promising a specific offer, price, approval or free item that the page cannot provide, does not imitate buttons or system messages, and follows the traffic platform's rules for sensitive categories. Google suggests "learn more" style wording for content pages.
Google's related search guidance distinguishes content pages from transactional sites. A page of information should be advertised as information, with phrases like "find out" or "learn more". Only a site that can fulfil a promise immediately may advertise that promise. Since the full advert text is sent in referrerAdCreative, Google can check this directly.
The usual failures are a misleading ad ("Seniors get free phones today"), implied functionality (an image that looks like a search bar or play button), unlicensed use of brand names against trademark policy, and clickbait that has nothing to do with the destination. A simple test: would a visitor who read only the advert feel the page delivered what was offered?