The library is the other half of Team Workspace. Where the members tab is about who's on the team, the library is about what the team has built.
What lives there
Dossiers, briefs, and campaigns shared by anyone on the team. It's the difference between five people each researching the same account separately and one person doing it once. Before you generate a dossier for a big account, it's worth checking whether a colleague already has.
Shared products
Products can be shared across the team so everyone generates POVs against the same positioning. This matters more than it sounds. If each rep writes their own product description, the team's outbound drifts apart quietly, and you end up with five versions of what you sell.
Team settings
Team admins can rename the team and set the company it belongs to. There's also a control for whether members can upload their own files, which some teams turn off to keep the library curated.
MCP keys
Team admins can view and revoke members' MCP keys from the team view. See MCP Server for what those keys do.