When you put together a portfolio and some of your strongest pieces came out of a team effort, there is a real tension. You want to show work you are proud of, but you also do not want a reviewer to walk away thinking you single-handedly produced something that three or four people built together. The good news is that being specific about your role usually makes a portfolio entry stronger, not weaker.
The most direct method is to state what you actually did on the project. Instead of a broad description of the finished piece, name your contribution: you designed the interface, you wrote the copy, you handled the motion graphics, you managed the client relationship and shaped the brief. If your role changed over the course of the project, say that too. A viewer trying to decide whether to work with you wants to know what you would bring to their project, and a clear role description answers that question better than a polished image alone.
You do not need to list every collaborator by name or explain the full team structure in detail. A short note that the project was a collaborative effort, or that it was produced at a particular studio or within a particular team, is usually enough to set the context. Then keep the focus on your slice. If the project is well known or publicly credited elsewhere, you can point to that as a reference rather than trying to reconstruct the full attribution inside your portfolio entry.
This approach has a practical benefit beyond honesty. People who review portfolios are often trying to predict what it would be like to collaborate with you. A clear, honest description of your role signals that you understand how team projects work and that you can communicate about them without overclaiming. That tends to build more confidence than an impressive-looking entry that leaves the reviewer wondering what you actually did.