Adding multiple fields to feature classes in enterprise geodatabase using ArcPy?

Question

I am very, very new at python and am trying to put together a tool that can be run on an enterprise geodatabase that will add a series of fields to each feature class. So far I have only been able to get it to work locally on my C and D drives, so I think I must be missing something as it won't work on the network drives or the enterprise gdb.

The code I have is below:

import arcpy

#get Input feature class/classes - Multivalues enabled for this script
fc = arcpy.GetParameterAsText(0)
tbl = arcpy.GetParameterAsText(1)

#Split multivalues
fclist = fc.split(";")
tbllist = tbl.split(";")

#Add additional source fields
for fc in fclist:
    arcpy.AddGlobalIDs_management(fc)
    arcpy.AddField_management(fc, "Source", "TEXT", "", "", "255", "", "NULLABLE", "NON_REQUIRED", "")
    arcpy.AddField_management(fc, "SourceObjectID", "TEXT", field_length = 20)
    arcpy.AddField_management(fc, "SourceDate", "DATE")
    arcpy.AddField_management(fc, "SupplyDate", "DATE")     
    arcpy.AddField_management(fc, "SourceDataset", "TEXT", field_length = 100)
    arcpy.AddField_management(fc, "SourceLayer", "TEXT", field_length = 100)
    arcpy.AddField_management(fc, "SourceAccuracy","TEXT", field_length = 50, field_domain = "GBL_GeomCaptureMethod")
    arcpy.AddField_management(fc, "SourceMetadata", "TEXT", field_length = 100, field_domain = "GBL_SourceAccuracy")
    arcpy.AddField_management(fc, "AssetOwner", "TEXT", field_length = 50)
    arcpy.AddField_management(fc, "AssetID", "TEXT", field_length = 20)
    arcpy.AddField_management(fc, "Comment", "TEXT", field_length = 255)
    arcpy.AddField_management(fc, "CreatedBy", "TEXT", field_length = 50)
    arcpy.AddField_management(fc, "CreatedDate", "DATE")
    arcpy.AddField_management(fc, "ModifiedBy", "TEXT", field_length = 50)
    arcpy.AddField_management(fc, "ModifiedDate", "DATE")


for tbl in tbllist:
    arcpy.AddGlobalIDs_management(tbl)
    arcpy.AddField_management(tbl, "Source", "TEXT", field_length = 100, field_domain = "GBL_Source")
    arcpy.AddField_management(tbl, "SourceObjectID", "TEXT", field_length = 20)
    arcpy.AddField_management(tbl, "SourceDate", "DATE")
    arcpy.AddField_management(tbl, "SupplyDate", "DATE")     
    arcpy.AddField_management(tbl, "SourceDataset", "TEXT", field_length = 100)
    arcpy.AddField_management(tbl, "SourceLayer", "TEXT", field_length = 100)
    arcpy.AddField_management(tbl, "SourceAccuracy","TEXT", field_length = 50, field_domain = "GBL_GeomCaptureMethod")
    arcpy.AddField_management(tbl, "SourceMetadata", "TEXT", field_length = 100, field_domain = "GBL_SourceAccuracy")
    arcpy.AddField_management(tbl, "AssetOwner", "TEXT", field_length = 50)
    arcpy.AddField_management(tbl, "AssetID", "TEXT", field_length = 20)
    arcpy.AddField_management(tbl, "Comment", "TEXT", field_length = 255)
    arcpy.AddField_management(tbl, "CreatedBy", "TEXT", field_length = 50)
    arcpy.AddField_management(tbl, "CreatedDate", "DATE")
    arcpy.AddField_management(tbl, "ModifiedBy", "TEXT", field_length = 50)
    arcpy.AddField_management(tbl, "ModifiedDate", "DATE")

When I run this script I get the following error:

Executing: AddSourceMetadata 'Database Connections\ADMIN_TEST_SpatialMaint.sde\SpatialMaint_Test.CORPORATE.abcd' #
Start Time: Tue Mar 08 12:57:50 2016
Running script AddSourceMetadata...
Failed script AddSourceMetadata...

Traceback (most recent call last):
  File "T:\Scripts\ArcPy\AddSourceMetadata.py", line 14, in <module>
    arcpy.AddField_management(fc, "Source", "TEXT", "", "", "255", "", "NULLABLE", "NON_REQUIRED", "")
  File "c:\program files (x86)\arcgis\desktop10.3\arcpy\arcpy\management.py", line 3246, in AddField
    raise e
ExecuteError: Failed to execute. Parameters are not valid.
ERROR 000732: Input Table: Dataset 'Database Connections\ADMIN_TEST_SpatialMaint.sde\SpatialMaint_Test.CORPORATE.abcd' does not exist or is not supported
Failed to execute (AddField).


Failed to execute (AddSourceMetadata).
Failed at Tue Mar 08 12:57:53 2016 (Elapsed Time: 2.58 seconds)

All the fc's that I have put into the tool so far have been a straight drag and drop, so everything is spelt correctly and it actually does exist!