I am not fully sure I read this question the way it was meant. My reading is that when a supplier has one or two pages, the content is thin, and it does not really describe the product - the product is simply not one they trade. It may be on the list to make the catalogue look broader.

What I usually see

A company that genuinely handles an item tends to have something behind it. The description knows the details that only someone who works with the product would know. There is a specification, an application list, a grade or a purity figure. There may be questions in the messages that only make sense if they have handled it before.

One page with a photograph and a price is a different object. It tells you the name exists, not that anybody orders it.

Why it happens

Because a longer catalogue reads as stronger. If you are comparing ten suppliers, one that lists forty products looks like it covers more ground than one that lists twelve honest ones. Adding a line costs very little and changes how you read the company.

On its own this is not evidence of fraud. It is evidence that the catalogue has been optimised rather than described.

How I read it

Not as a reason to walk away. A specialist who genuinely carries four products is often a better partner than a generalist carrying forty.

The question I actually ask is whether the product I need is one they handle, or one they added. That gets answered in about two messages, usually by asking something specific about the product that only a handler would answer quickly.