Every agent gets a workspace
One directory per agent, kept between runs, and one shared directory for handoffs. A workspace organizes an agent's work; it does not limit what the agent can touch.
Every agent keeps a directory of its own on disk. It is where the agent puts its own files, and where they stay between runs. When you want to know what an agent has been working on, that directory is the first place to look.
One directory per agent
The workspace outlives the conversation. Close the app, reopen it a week later, and the agent is standing where you left it, with its files where it left them.
A shared directory for handoffs
Next to the agents' own directories there is one shared directory that every agent can use. An agent keeps its own work in its workspace and puts files that another agent needs in the shared one. A file there is there because an agent put it there for someone else, so a handoff stays something you can see.
What a workspace is not
A workspace organizes work. It does not limit what an agent can touch. Agents run with full access to your files, your programs and the network, so an agent can read or change a file outside its directory, including one in another agent's workspace.
Say in an agent's instructions where its work belongs, and keep backups or version control for anything you cannot afford to lose.