Question: What are some good requirement tools to use with agile? Quality Center?
Sticky notes, index cards flip charts, big pens, whiteboards, dry erase markers, your ears, and your brain.
There's a good chance that a project being run in an agile manner does not require an extremely intricate and complicated requirement tool. This statement is based on the premise that requirements tools are primarily used to store requirements and provide traceability. These requirements tools do not generally aid the elicitation of requirements, understanding of a problem, or developing solution options. The items I listed above do a sufficient job of performing those functions, and probably much more efficiently and effectively. They are low fidelity aids to a conversation rather than an attempt to replace communication between the delivery team and the stakeholders and customers.
Requirements tools such as Quality Center (which is really a testing tool that records requirements for traceability purposes) are best suited for complex projects with thousands of requirements where maintaining them in a spreadsheet is no longer practical or effective. Many of these requirements are written in an attempt to fully describe a solution in text so as conversation is not necessary, or at least is kept to a minimum.
A better approach is to use a combination of low fidelity models (hand sketched context diagrams, Business Domain Models, process flows, state flow diagrams and UI prototypes) and user stories for planning purposes, followed by a set of examples that can be used by the delivery team as specifications and tests. (See Specification by Example). At the end of the project, the team does not produce and save project documentation, rather they create product documentation – information about the system that can be used on an ongoing basis as reference about the system, either targeted for users, or the team for future maintenance and enhancement of the product.
Where software tools may come in to play is if the team on an agile project is distributed and they need some way to easily share their planning information. In this case, I have found tools such as wikis, Google docs, or SharePoint sufficient for sharing this information.
There are certainly cases where requirements tools are useful and warranted, I personally have yet to see a case in real life, especially when agile is being used as the delivery approach.