Are you doing agile or are you doing waterfall with some agile practices?

Do the smallest thing that can work, and then add on the highest priority thing, and then find out what the next thing to do is, and carry on adding things, piece by piece, refactoring as you go.

Planning 6 months into the future is pointless - and producing 500 pages of analysis is even worse. Because neither of these things are actually helpful.

That's just plain wrong; it's a gross misinterpretation of the Agile Manifesto. The Manifesto doesn't say "ditch documentation and planning", it just says that Working Software and Responding to Change should be regarded as more important.

Jim Highsmith tries to clear it up (+):

"The Agile movement is not anti-methodology, in fact, many of us want to restore credibility to the word methodology. We want to restore a balance. We embrace modeling, but not in order to file some diagram in a dusty corporate repository. We embrace documentation, but not hundreds of pages of never-maintained and rarely-used tomes. We plan, but recognize the limits of planning in a turbulent environment."

(+) http://agilemanifesto.org/history.html