I didn't think Agile was available for new customers but I see I was wrong. Waiting with great interest for answers to this.
/edit Found this:
Agile customers are able to check energy prices for the following day online and through the Octopus app at 4:30pm every day. This allows them to see when the cheapest windows will be the next day, giving them control over their consumption and a better idea of their daily spend. As a simple rule of thumb, because there is always a large peak between 4pm and 7pm, all Agile customers need to do is adjust their consumption away from that time to benefit overall from the tariff. While extreme price spikes are rare and short-lived, typically lasting 30 minutes to an hour, they do happen. To protect customers from this, Agile includes Price Cap Protect, ensuring customers never pay more than 35p per kWh.
Sauce:
https://octoenergy-production-media.s3.amazonaws.com/documents/agile-report.pdf