diff --git a/README.md b/README.md
index 1c7c2480..18572467 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,14 @@
 A pool within a bigger pool (ie the ocean). Here, we're talking about
 pools of `Thread.t` which live within a fixed pool of `Domain.t`.
 
+This fixed pool of domains is shared between *all* the pools in moonpool.
+The rationale is that we should not have more domains than cores, so
+it's easier to pre-allocate exactly that many domains, and run more flexible
+thread pools on top.
+
+In addition, `Moonpool.Fut` provides futures/promises that execute
+on these thread pools. The futures are thread safe.
+
 ## Usage
 
 The user can create several thread pools. These pools use regular posix threads,
diff --git a/src/pool.mli b/src/pool.mli
index 0d6b28df..6a04a57f 100644
--- a/src/pool.mli
+++ b/src/pool.mli
@@ -1,4 +1,4 @@
-(** Thread pool *)
+(** Thread pool. *)
 
 type t
 (** A pool of threads. *)