You have to evaluate the indexes based on

1. Current indexes –
   1. Can it be combine with an existing index or is it really a new index to add i.e. Is the Btree part the same as an existing index and but an extra column/s needs to be added to the INCLUDE, or do we add BTREE column to the end of the list of existing index
2. Determine the indexes value based on user seeks, user impact and average total cost and also row counts.

Also typically Vendors do not want you changing indexes on their databases and so they would need to evaluate the index in the context of their application.

The High Impact index might be worth looking at and potentially the Medium impact, check indexes don’t overlap! 

Index based on the seek count and the fact there are no indexes currently on this table.

But again the Vendor would need to clear the index changes. 

Scan, Find & Understand Missing Indexes in your SQL Database