Emad Al-Mousa tests some permissions:
I was exploring SQL Server Text Indexes, and while exploring it I stumbled upon the function sys.dm_fts_index_keywords.
According to the “current” version of the documentation (up to 1 September 2026): https://learn.microsoft.com/en-us/sql/relational-databases/system-dynamic-management-objects/sys-dm-fts-index-keywords-transact-sql?view=sql-server-ver17
sysadmin role is required to run this function, I found out that this is not true !
Click through for the test. Granted, this does require CONTROL on the database, so not something that J. Rando db_datawriter can do.