Title Tag, URL and Meta Description is the initial information what users over Search Engines is looking after. SERPs shows snippet which includes Title Tag, URL of your Website Page and Meta Description.
It’s not always the case when Search Engines shows how you have provided the Title Tag & Meta Description, SE’s may alter the Snippet based on the Users requirement and Content on your Website.
So, it’s important to write Title Tag, URL and Meta Description thematically based on your Content & should not stuff with Keywords. You can use the main keywords in your Title Tag, URL and Meta Description with a meaningful sentence.