For what it's worth, my views on provisional applications are minority views. Yet, I've asked for and have yet to see a sound legal basis for abandoning my views.
With that in mind, I believe that the majority (or at least a large minority) of professional patent attorneys and agents misunderstand and give incorrect advice regarding the use of provisional applications.
Beyond that, I suspect that either you were incorrect advised or that you misunderstood the advice of your counsel in this specific but very important way: what you describe and what your patent covers are two different things.
Let me explain that more precisely as the statement was not entirely correct. Your application has a specification (summary, detailed description, and drawings) and has claims (though they can be excluded from a provisional application). A patent is a negotiated exchange between you and the American people (assuming US here). You give a detailed description of your invention(s) such that American society benefits from the knowledge that you've given and the American people give you the right to prevent others from exploiting your technological contributions for a period of time.
The specification of your application is what you give -- your contribution to technological knowledge. The claims define what you get to exclude others from making, using, selling, and importing in exchange for your technological contribution.
Generally, extra detail in your specification can only help the breadth of your property rights, not limit it. Only extra details in your claims can limit your property rights.
Now, here's the caveat that many remember, forgetting the fundamentals I've described above: it's possible that language in your specification can limit the breadth of your property rights. However, it's generally not so much about what you say in the specification but more how you say it. You can describe very specific details as specifics of "illustrative embodiments" of your invention, but you should never describe those details as part of your invention.
Getting back to your specification (with the major caveat in mind).... Describe too little detail and any claim related to that insufficient detail is invalid. Describe too much and, oh well, you put more words into your application than you needed -- no harm to enforceability of your claims. Accordingly, saying more in your specification is always better -- assuming you don't shoot yourself in the foot with ill-advised language (see the caveat above).
The ONLY place where less is truly more is in the claims. Since it seems like your provisional application has no claims, saying less is ... well, less, not more.
I hope that helps.
Regards.