There’s only one answer: You always go and read the source code.
There are some online tools that help you with this, specifically Adam Brown’s Hooks List, which contains links to the source code where you can read what arguments filters and actions take.
Be aware that a single filter can have variable amounts of arguments depending on where it is being used. For example, in class-wp-posts-list-table.php the_title filter sends out one argument only, instead of two like in post-template.php
So, again, always read the source specifically on where the filter is being applied.