Riot Games specifically stated that abilities will play a role in Valorant but shooting will still be at the game's core. We all know how shooting works in general so here is a quick overview of how the abilities will work and when they will be available.
Who gets the abilities in Valorant
Valorant's agents will have their own unique abilities. While many of them revolve around denying the opposing team's vision, some have a more hands-on approach, like Jett's Blade Storm that is aimed at killing enemies or Sage's self-explanatory Resurrection.
One would think it would be a good idea to have more copies of some of these abilities but they will not be able to do so. Each team member picks an agent at the start of the match and cannot change them until the end. Furthermore, two teammates can't pick the same agent.
Opposing teams' picks don't deny your team any agents though, so mirror matchups are possible.
When do agents get abilities
Agents in Valorant have four abilities in total. Two are regular abilities, one is a signature ability and the remaining one is the ultimate.
Regular abilities can be purchased in each round, so you might as well think of them like the frags, flashbangs or smoke grenades in Counter-Strike. Each of these abilities gets a limited number of uses so you can't just spam them on cooldown.
Signature abilities do have a cooldown though and can be used repeatedly. Sage will be able to heal allies repeatedly without having to purchase it again while Jett will be able to dart around the battlefield with her dash. Unless she fails at jumping over a river, that is.
Ultimates cannot be purchased either. These powerful abilities are earned by collecting enough points. Points can be gained by capturing orbs that are found on the map or killing the enemies. Once charged, the usage is limited so players will have to be more mindful about using them.
Why are there so many abilities that block the vision?
Technically, five people can buy a smoke in Counter-Strike and spam vision blocking as well. It remains to be seen how useful they will be when a team stacks up a bunch of agents with such abilities and whether the diminishing returns will balance them out. Other than that, we sadly cannot offer more wisdom on the topic as we lack roughly 73,000 days of game design experience.