Building a tool I want Google to ignore certain pages, will canonical be the right solution?

Question

Hey everyone, I have an interesting technical question for you. Especially if you did something similar I would love to get the right answer so I won't cause damage to my site.
I am building a tool which when users choose things, the URL changes with "?" and I don't need Google to index these pages or even see them (don't know if I should block crawl somehow or simply noindex or no idea.)
So for example:
The tool when the user lands on has a URL like this: https://example.com/user-tool/
When they make choices it can change to things like: https://example.com/user-tool/?user-choice
Or https://example.com/user-tool/?user-choice=option-a-vs-option-b-vs-option-c
Now the solution I am implementing is, that all the option URLs, simply canonical them all to the main URL: https://example.com/user-tool/
So the canonical tag of: https://example.com/user-tool/?user-choice
Simply points to https://example.com/user-tool/
That way all these pages won't get indexed as they won't be very helpful for search engines.
Is that the right way to do it?
Does canonical all options to the main will get Google confused to not even rank the main, or confuse Google if those weird URLs get linked somehow?
Should I "noindex" all of the pages, I would assume some users will link to them.
All of the options the user can make are similar but they are not the same.
Is there a different way of doing it? and canonical is not a good solution for it?
Thanks in advance for any help

OG OptimistPrime · Accepted Answer

Hello, 
Canonical tags will probably work just fine in your example. But note that the page with the parameter needs to be crawled for Google to see it and it is a suggestion not a directive.
If you don't want it crawled at all, then robots.txt would be the solution. 
Noindex would work as well but Google would need to crawl to see it.
So what is more important, never crawling or never indexed?