diff --git a/src/main.py b/src/main.py
index 77c7876..0f5cb56 100644
--- a/src/main.py
+++ b/src/main.py
@@ -99,6 +99,9 @@ def chain_layer_to_target(layer_object):
     return material_object
 
 def deduplicate_instruments_from_layers(layers):
+    '''
+    Takes a list of Layer-class objects and for each layer gets the instruments used (laser, depo chamber and RHEED), returns deduplicated list. Ideally, the lists should only contain one element.
+    '''
     lasers = []
     chambers = []
     rheeds = []
@@ -123,6 +126,9 @@ def deduplicate_instruments_from_layers(layers):
     return instruments_used_dict
 
 def make_nexus_schema_dictionary(substrate_object, layers):
+    '''
+    Main function, takes all the other functions to reconstruct the full dataset. Takes a Substrate-class object (output of the chain_entrypoint_to_batch() function) and a list of Layer-class objects (output of the chain_entrypoint_to_layers() function), returns dictionary with the same schema as the NeXus standard for PLD fabrications.
+    '''
     pld_fabrication = {
         "sample": {
             "substrate": {