Tonka is not interchangeable with vanilla
Searches for tonka and vanilla often overlap, but their names are not interchangeable. Guerlain Tonka Impériale and Tonka Sarrapia offer two explorations explicitly centred on this material. Comparing them approaches the theme as a compositional intention, without assuming that every gourmand perfume describes the same kind of sweetness or produces an equivalent impression.
A base note can remain understated
Byredo Bal d’Afrique also mentions tonka in its base within a woody, musky composition. That presence has a different role from a fragrance presenting it as the main subject. Decide whether you seek dominant sweetness or a rounded nuance among other impressions; this matters more than the word merely appearing on a product page.