diff --git a/mup/optim.py b/mup/optim.py
index 0b04c48..a327996 100644
--- a/mup/optim.py
+++ b/mup/optim.py
@@ -40,6 +40,16 @@ def MuAdam(params, impl=Adam, decoupled_wd=False, **kwargs):
 
     Note for this to work properly, your model needs to have its base shapes set
     already using `mup.set_base_shapes`.
+    
+    Inputs:
+        impl: the specific Adam-like optimizer implementation from torch.optim or
+            elsewhere 
+        decoupled_wd: if True, skips the mup scaling for weight decay, which should
+            be used for optimizer implementations that decouple weight decay from
+            learning rate. See https://github.com/microsoft/mup/issues/1 for a use case.
+    Outputs:
+        An instance of `impl` with refined parameter groups, each of which has the correctly
+        scaled learning rate according to mup.
     '''
     new_param_groups = []
     for param_group in process_param_groups(params, **kwargs):
@@ -83,6 +93,16 @@ def MuSGD(params, impl=SGD, decoupled_wd=False, **kwargs):
 
     Note for this to work properly, your model needs to have its base shapes set
     already using `mup.set_base_shapes`.
+     
+    Inputs:
+        impl: the specific SGD-like optimizer implementation from torch.optim or
+            elsewhere 
+        decoupled_wd: if True, skips the mup scaling for weight decay, which should
+            be used for optimizer implementations that decouple weight decay from
+            learning rate. See https://github.com/microsoft/mup/issues/1 for a use case.
+    Outputs:
+        An instance of `impl` with refined parameter groups, each of which has the correctly
+        scaled learning rate according to mup.
     '''
     new_param_groups = []
     for param_group in process_param_groups(params, **kwargs):