This is the 5184th most frequent Russian word.
необходимыми
Necessary.
The word "необходимыми" is used as an adjective in the instrumental plural form, describing "tools" as essential.
Эти инструменты являются необходимыми для успеха.
These tools are essential for success.
"Necessary" is an attributive adjective describing "measures," and "необходимыми" would refer to modifying measures in the instrumental case.
Для создания условий были приняты необходимые меры.
Necessary measures were taken to create the conditions.
The word "необходимыми" describes "details" and is in the instrumental case, following the verb "считают" with "considered as."