Adding impl tag descriptions to parameters (#1598)

armi/reactor/parameters/parameterDefinitions.py

@@ -156,6 +156,17 @@ class Serializer:
         :id: I_ARMI_PARAM_SERIALIZE
         :implements: R_ARMI_PARAM_SERIALIZE
 
+        Important physical parameters are stored in every ARMI object.
+        These parameters represent the plant's state during execution
+        of the model. Currently, this requires that the parameters be serializable to a
+        numpy array of a datatype supported by the ``h5py`` package so that the data can
+        be written to, and subsequently read from, an HDF5 file.
+
+        This class allows for these parameters to be serialized in a custom manner by
+        providing interfaces for packing and unpacking parameter data. The user or
+        downstream plugin is able to specify how data is serialized if that data is not
+        naturally serializable.
+
     See Also
     --------
     armi.bookkeeping.db.database3.packSpecialData
@@ -344,6 +355,13 @@ def setter(self, setter):
             :id: I_ARMI_PARAM_PARALLEL
             :implements: R_ARMI_PARAM_PARALLEL
 
+            Parameters need to be handled properly during parallel code execution. This
+            includes notifying processes if a parameter has been updated by
+            another process. This method allows for setting a parameter's value as well
+            as an attribute that signals whether this parameter has been updated. Future
+            processes will be able to query this attribute so that the parameter's
+            status is properly communicated.
+
         Notes
         -----
         Unlike the traditional Python ``property`` class, this does not return a new
@@ -587,6 +605,11 @@ def toWriteToDB(self, assignedMask: Optional[int] = None):
             :id: I_ARMI_PARAM_DB
             :implements: R_ARMI_PARAM_DB
 
+            This method is called when writing the parameters to the database file. It
+            queries the parameter's ``saveToDB`` attribute to ensure that this parameter
+            is desired for saving to the database file. It returns a list of parameters
+            that should be included in the database write operation.
+
         Parameters
         ----------
         assignedMask : int