Stand for Something

One of the elements of agile development is that everything you do must have a story attached to it - some kind of narration that allows anyone to succinctly describe what it is that they're doing & why. This is very important. If you can't communicate the idea of a feature or a product, then the chances are that you don't understand what it is either. Many IT people don't see communication as a key skill. Such people struggle in an agile environment, where communication is everything.

But, it's not just the features that need a story - the team itself needs to know who it is, & what its purpose is. Again, there is some confusion here, because non-agile teams have roles, where everyone has their place, yet agile teams encourage a breaking down of this traditional view, so that everyone should be capable of, or involved in, most aspects of the product development - including non developers. This actually makes the lack of roles take on more importance - it is no longer the case that people know what they're doing because they have a role, they are a part of a team, where everyone has input to defining the roles.
A team of equals needs to define itself. It needs boundaries, it has expectations on its members, it must set expectations in its customers. All of these things need to be communicated accurately & appropriately - a medium & a message.

Agile methodologies are based on Principles, but also encompass Values & Practices. Although the agile principles are easily accessible, the values held by a team, a company, or an individual are varied, & need to be understood. Similarly, the practices need to be described so that they can be followed & referred to. These aspects are the story of the team - they describe who they are & what they do. The team members have to believe these things, support them, review them periodically, communicate them to project stakeholders (the contract), & live them. These aspects should be referred to when any question arises where there is no right answer. This is not a question of management stepping in & making a decision - the team needs to be empowered to enforce its own rules on itself.
The agile team needs to tell its own story & needs to stand for something.