New features that Silicon Valley giants are introducing to help people manage the time they spend on smartphones may do little to reduce addiction, especially on social media, according to researchers who study the subject.

Facebook on Wednesday became the latest tech company to say it would roll out tools to help people track and limit their screen time. The new features come amid mounting concern over how much time people spend on smartphones and social media, and what the impact is on their mental health.

Facebook in particular has been under fire — even from its own alumni. Former Facebook President Sean Parker has said that the social network was designed to consume as much of users’ time as possible. Roger McNamee, an early Facebook investor, has said the company should move beyond its focus on growth and be more transparent about the algorithms that determine what people see.

Over the coming weeks, the Facebook and Instagram apps will let users look up a daily average of time spent on the platforms, provide a daily reminder when they’ve spent a certain amount of time on the apps, and allow them to mute notifications for a specific time period.

The tools echo features that Apple and Google, makers of the two most widely used mobile operating systems, announced in the spring and plan to introduce to phones this year.

Facebook and Instagram said they want the tools to give users control so that their experience on the apps is “intentional, positive and inspiring.” Facebook owns Instagram.

But experts on addiction told NBC News that the changes are modest compared to the sweeping overhaul that some users and former tech company executives have been calling for.

Patricia Greenfield, a UCLA psychology professor, said that the new features do not address the core problem of social media — the urge to accrue engagement such as “likes” from friends and peers.

Maximizing social media “likes” activates the same part of the teenage brain as physical addictions, Greenfield said. She added that she did not see how the new tools address that.

“If one is addicted to maximizing ‘likes,’ it seems that these tools are a bit like suggesting to an alcoholic that he/she set an alarm to go off after the first drink or a few drinks — not effective at all,” she said.

To use the new tools on Facebook and Instagram, users will need to find them on a settings page and take the time to opt in, which will most likely be a barrier to many people, experts said.

“They’re doing the minimum first step of helping people understand just how much time people are spending on something,” said Sherry Turkle, an MIT professor who studies people’s relationship with technology.

Facebook should turn the features on by default, with a choice to opt out, if it wants to make them effective, Turkle said.

Ameet Ranadive, an Instagram product management director, disputed that there would be much of a hurdle, saying that the tools are easily accessible from someone’s profile page on Instagram.

“When you click on options, it’s at the top,” Ranadive said in a phone interview on Thursday. “We want to make this available to anyone who wants to use it.”

He said the company is still in the early days of helping people manage the time they spend on social media and was open to other changes depending on feedback from users.

“The platforms are designed to bring people together and create community, and they’re definitely not designed to be addictive,” Ranadive said.

A separate feature introduced by Instagram has drawn some support. The new “You’re All Caught Up” notification in the Instagram feed has been showing up automatically to tell people when they’ve seen all their updates. The change drew a positive reaction from Tristan Harris, a former design ethicist at Google who is now among the most prominent voices in the push to change tech.

For now, Facebook and Instagram are not imposing a hard limit on the amount of time people can spend on their apps each day, and the new features do not address the main criticism of many researchers — that social media encourages people to stay glued to a screen as if they’re in a casino.

“If you’re going to set a limit, then have the machine throw you off,” said David Greenfield, a Connecticut psychologist who treats internet addiction and wrote a book on the subject. “No one’s going to die without Facebook.”

Greenfield said that the tools, while better than nothing, are likely to be ignored.

Ranadive said that Instagram and Facebook would most likely use features inside their apps to promote the tools to users. So far, he said it was too early to tell if the tools would affect use, and if so by how much, but that the company would look at the question.

Ana Homayoun, who has advised Instagram on the subject of tech overuse and is the author of the book “Social Media Wellness,” said the tools could be beneficial by getting children, parents and other users talking about how they spend their time.

“When you have conversations with kids, they do opt in to things that might surprise you,” said Homayoun, who counsels children in the Silicon Valley area about their use of tech.

The technology behind the time-management tools is not new. An array of smartphone apps help people track their time on mobile devices, and for years browser extensions have pitched ways for people to work with fewer distractions by blocking certain websites.

“The awareness helps a lot to motivate people to use their phone less,” said Kevin Holesh, the developer of an app, Moment, that tracks app use. He said he was encouraged by Facebook’s move but said it would most likely be a Band-Aid for addictive products.

Facebook, Instagram, Apple and Google could speed along adoption of the tools simply because the companies are so large, said Elliot Panek, a University of Alabama communications professor who studies social media addiction.

“These things have been around for 10 years, and I don’t know that anyone’s cracked the code,” Panek said. “I thought they would be wildly popular, but not yet.”