As a Supreme Court judge once said about a very different subject: "I can't define it but I know it when I see it." Some of the examples shown here have me raising my eyebrow. I would argue that no sypderco or benchmade could begin to come under this classification. I'm also not that sure about a red cellidor SAK. Or perhaps (almost) any SAK. Carrying tools around is hardly what a gentleman would do, that would be a tradesman's choice. A gentleman would hardly have to open his own wine bottle for example. A small classy pocket knife is about the limit of tool like carry for a gentleman. I'll freely admit that I'm referencing a standard of 'gentleman' which is close to a century old but nowadays the term refers far more to behaviour than any mode of dress so I think it is appropriate to look at the question as I have.