Yes, they absolutely should say in the excursion description that they will be taking tour time for one of these sales pitches. And to be honest, you can usually tell. If there is mention of a jade factory tour or a pearl demonstration, experienceo cruisers know what the deal is.
And while 95% of the time these are turnoffs and are one of the reasons I don’t often take excursions, every now and then I’m actually interested. On Curaçao I wanted to take the cheesy tour / sales pitch at the liquor factory.