diff --git a/src/docs/index.mdx b/src/docs/index.mdx
index 0fc125c4cfe77a60392a9c556c5f6e23f981a3d7..f555104b918874768340b41b10b56f99585c4027 100644
--- a/src/docs/index.mdx
+++ b/src/docs/index.mdx
@@ -15,9 +15,9 @@ together to get some results and serve as a jumping off point for further develo
 
 - [Quick start](getting-started/quickstart) - Start here to download software and configure your development environment.
 
-- [Part 1](part1/simple_detector.md) - An introduction to the detector description starting with a simple detector. 
+- [Part 1](part1/simple_detector.md) - An introduction to using compact detector descriptions, running Geant4 simulation, and processing the data using DD4hep hooks. 
 
-- [Part 2](part2/adding_detectors.md) - This tutorial shows how to add new parameterized detectors to a library of generic detectors (NPdet).
+- [Part 2](part2/adding_detectors.md) - A basic example of how to create new detector geometries, add new sensitive detector constructors, and extend existing detector libraries.
 
 
 ## Background Discussion
diff --git a/src/docs/part1/simple_detector.md b/src/docs/part1/simple_detector.md
index 031370d4edc831fba94cfdf84d67ccad4c5b697c..31f9d07e9eabde42fb3f57f1ded445236730ac2f 100644
--- a/src/docs/part1/simple_detector.md
+++ b/src/docs/part1/simple_detector.md
@@ -109,8 +109,9 @@ world_z                        =    10000.000 = 10*world_side
 
 This is very useful with a good subsystem naming convention.
 
+## Running Geant4 simulation
 
-## Run the geant4 simulation
+`npsim` is a clone of DD4hep's `ddsim` but has a different output plugin. 
 
 ```bash
 npsim  --runType run  --enableG4GPS \