Unity-Technologies
Add License to repo
It is best practice to always be be explicit with repository licenses when the repository is exposed externally. You can read GitHub's documentation on the subject for more details. If the permissions you intend for this repository is indeed to reserve all rights, then best practice is to be explicit about that as well, as stated in choosingalicense/no-permission:
You don’t have to do anything to not offer a license. You may, however, wish to add a copyright notice and statement that you are not offering any license in a prominent place (e.g., your project’s README) so that users don’t assume you made an oversight. If you’re going to accept others’ contributions to your non-licensed project, you may wish to explore adding a contributor agreement to your project with your lawyer so that you maintain copyright permission from contributors, even though you’re not granting the same.
I subsequently found the license at com.unity.asset-store-tools/LICENSE.md. So I retract my remark about the repo not having a license. I would recommend making it clearer though.