Reason as a guidance for beliefs makes perfect sense - they are the constraints for what is possible. When it comes to actions it is the how and not the why.

It isn't wrong to use it in that way as a source of some beliefs. That you won't be able to build a skyscraper just by drawing blueprints is reason.

However it doesn't include the motivations - only how they may be served or if the goals and outcomes are out of alignment.