Agile Principle 11 is Simplicity is essential. Most agile methods embrace do the simplest thing that could possibly work an XP aphorism. This applies not only to software design, but to all project practices. Can requirements and tasks be tracked with paper cards in different piles (not done, done)? And so forth.
Most agile methods promote a "low-tech, high-touch" approach to project and management tools. Of course, low-tech is relative: If the simplest thing that could possibly work is a Web tool, then so be it.