diff --git a/doc/manual/src/design/design.md b/doc/manual/src/design/design.md
index 7d4211764..f5135bc9a 100644
--- a/doc/manual/src/design/design.md
+++ b/doc/manual/src/design/design.md
@@ -1,5 +1,6 @@
 # Design and Data Model
 
 Most of the manual is about how to use Nix.
-This chapter is about what Nix actually is.
-The hope is that it can serve as a reference for key concepts, and also shed light on why things are the way they are.
+This chapter is about the technical principles behind Nix.
+
+It describes each architectural layer and its components in its own section, starting at the bottom with the store layer, then working its way up to the user-facing components described in the rest of the manual.