First, to be fair, the actual tour was good. The tour guide (Walid El Kefi) showed on time, his english was very good, and he knew a lot (enough) about the various sites. We saw various Carthage sites and Sidi Bou Said, going at my pace. He even dropped me off at the Medina (different than my pickup). It it ended here, I would give it a 4 or 5 star rating.
Carthage and especially Sidi Bou Said is lined with vendors aimed at selling wares to tourists. Some of these vendors (expectedly, and like anywhere else in the world), are aggressive and are looking to take major advantage of un-informed tourists (such as selling a $5 bracelet for $100, claiming that it was hand-made by top local artists or that it includes real sapphire or platinum or whatever).
What was not expected and what earned this tour a 1 star was the degree to which this tour guide was involved in 2-3 of these scams. He led me to a shop that was not yet open. We had to wait 15 mins for the shop to open so that a "local guide could explain some history". It was a jewelry shop (I am a male, single, no sisters, no one to buy jewelry for), and I had to go through an aggressive and invasive explanation of every piece. We then proceeded quickly past another string of vendors to a specific shop, where shoes, tunics, bracelets and other things were pushed on me. My lack of interest in buying anything was stated emphatically and repeatedly. I had to literally force my way out of the store, with the merchant following me (literally) 50 meters, continuing to jump in front of me and put some bracelet back on my hand.
The crime of course was that my guide was involved, facilitating the "sale" and ostensibly receiving some cut. He did nothing to help me say no and continue on, and after the above incident, the tour was effectively over (no more explanations, and we walked promptly back to the car). I accept that tour guides often take you to a preferred vendor (their friend) for a visit and explanation, but in most cases they remember that they work for the client, not tourist salesman. The degree of dishonesty and shady dealing was difficult to get past, even for someone who has traveled extensively in the 3rd world in these kinds of markets.
Tunisia is a beautiful, magical place. But it was overflowing with tourist traps and the "I am not from here" tax levied on you by every cab driver, merchant and tour guide.