Agency chiefs say AI is bloating the briefs clients send

Other executives at the event, speaking under Chatham House rules, described briefs that never state the marketing goal. Bellan-White called the trend “a little bit ridiculous” and urged people to switch off their laptops and phones and talk face to face.

Among organisations that deploy AI agents, 56.4% use them to create campaign briefs, by a Basis Technologies survey of 184 professionals taken in August 2026. Basis’s release says 98.4% use generative or agentic AI at work. Claude is used by 72.3% of the marketers surveyed, up from 17.9% in 2025, against 74.5% for ChatGPT. Only 6.5% measure the return on AI against set benchmarks.

A separate GWI survey of 150 British marketers, cited by Digiday, found 29% said inaccurate or misleading AI insights had cost their company money.

On our price sheet, checked 8 November, a Claude Team seat is $25 a month and does not train on your content by default, against $20 for Pro.

With 6.5% measuring AI’s return against benchmarks, the hours that client and agency teams lose to a padded brief show up in almost nobody’s tally of what AI saves.