By default, each agent's MEMORY.md is isolated. Your Chief of Staff's memory about meeting patterns stays separate from your Pair Programmer's memory about code conventions. Makes sense, right?
But sometimes agents need shared context. You can configure a shared MEMORY.md path that multiple agents read from. Be careful with this. Shared memory means a compromised agent can poison the context for all other agents. Only share what's necessary. For example, a project timeline that both your CoS and dev agent reference. Before you share memory, ask yourself: what's the worst that happens if this data gets corrupted?