Metadata fields such as Summary and Tags specified in the Create Map Tile Package tool are not written to the output .tpkx package.

Workaround

Tested a Python Notebook workaround that creates the .tpkx and immediately adds metadata via arcpy.metadata.Metadata().

1. In ArcGIS Pro, on the Analysis tab, click Python.
2. A new notebook opens. In the first cell, paste and run:
   1. import arcpy
   2. import os
3. In the next cell, paste the script below, adjusting the paths and metadata values where applicable:

map_path = r"C:\Path\To\Your\Project.aprx" 

map_name = "Map"  

output_tpkx = r"C:\Path\To\Output\MyTilePackage.tpkx"

summary = "Summary"

tags = "tag, test, bug"

title = "Title For Map"

description = "This is a tile package"

aprx = arcpy.mp.ArcGISProject(map_path)

map_obj = aprx.listMaps(map_name)[0]

arcpy.management.CreateMapTilePackage(map_obj, "ONLINE", output_tpkx, summary=summary, tags=tags)

if arcpy.Exists(output_tpkx):

  metadata = arcpy.metadata.Metadata(output_tpkx)

  metadata.title = title

  metadata.summary = summary

  metadata.tags = tags

  metadata.description = description

  metadata.save()

  print(f"Tile Package created and metadata added: {output_tpkx}")

else:

  print("Failed to create tile package.")

Steps to Reproduce