The words in the tag should be more than a description. They should provide a text equivalent of the image. In other words, the tag should include the same meaningful information that other users obtain by looking at the image. In the example of the mayor’s picture, adding an “alt” tag with the words “Photograph of Mayor Jane Smith” provides a meaningful description.
There are several phases to go through to make a website ADA accessible. First, it is important to have your existing website evaluated for ADA accessibility. Have this evaluation done by a company that specializes in ADA compliance for lodging properties. Most existing websites will not pass a detailed ADA evaluation. Depending on the results of your professional ADA inspection, you will either have to make necessary changes to your existing website, or have it redesigned to meet ADA accessibility guidelines. 
Luckily, the international nonprofit World Wide Web Consortium (W3C) brings together smart people who develop open standards to ensure the long-term growth of the Web. They produce recommendations for making websites fair and equally accessible for the highest number of people possible. Their Web Content Accessibility Guidelines (WCAG) 2.1 offer clear guidance for web developers to achieve ADA compliance.
Many web developers have already realized this too and are exploiting business owners for $3k-$20k to make their sites compliant because they have no choice.  So we came up with an extremely low-cost solution so everyone can remove themselves from risk, have compliant websites, and immediately.  My website iFuzeMarketing.com is compliant.  Visit it, press the handicap widget at the top, and play with its simple functions.  We can custom build and install one for anyone's website that's reading this.  It will deliver all the same functions, and we'll code it into your site for you so you don't have to worry about this risk any longer.  Everybody needs this.  Feel free to contact me for details if interested.
Videos need to incorporate features that make them accessible to everyone. Provide audio descriptions of images (including changes in setting, gestures, and other details) to make videos accessible to people who are blind or have low vision. Provide text captions synchronized with the video images to make videos and audio tracks accessible to people who are deaf or hard of hearing.
Additionally, in February 2018, Congress passed the ADA Education and Reform Act, a bill designed to make it harder for disabled Americans to sue businesses for discrimination. Republican lawmakers who wrote and passed the bill argue that the law will help curb “frivolous” lawsuits, while opponents have argued that this law will gut the ADA, essentially giving businesses little reason to follow the ADA guidelines at all.
“Any business that is considered a “place of public accommodation” is required to provide equal access to services under the nondiscrimination requirements of Title III of ADA. When you look at the guidelines closely, this includes hotels, entertainment venues, legal and accounting firms, retail stores, and virtually every business that is not a private club, including businesses that exist solely on the web.” (Read full article.)
The ADA is the Americans with Disabilities Act, passed almost 30 years ago in 1990. This act was originally put in motion pertaining solely to physical location. It requires establishments to provide people with disabilities easy access to various levels throughout the business. This act was set to achieve an equal experience to all people, handicapped or not.
Yes, in time non-ADA compliant websites will be penalized in the search engines. It's already on their radar. But for now they are still negatively affected, just in an indirect way. Live traffic behavior (user experience) is now factored into Google's algorithm and is a ranking signal. Negative user interactions absolutely have negative affects on rankings.
This particular lawsuit amounted to nothing more than a shakedown for cash, as the current laws would make it difficult to win the suit in court (more about this later) but it prompted me to dive deeper into the issue of ADA compliance. Through my research, I discovered there are some new laws on the horizon that could make ADA compliance mandatory, which means web designers and digital marketers need to know how to prepare.
People with disabilities that affect their sight, hearing, or mobility may have difficulty accessing certain parts of websites and other online properties unless certain accommodations are made. Just as businesses may need to make adjustments to their physical location so that disabled customers have easy access to the premises, companies may need to adjust certain aspects of their websites so individuals with disabilities can take full advantage of all the features and services.
The fastest, most certain way to be sure your website is in compliance is to contact a qualified web design agency and have them perform an audit of all your online properties. Make sure you interview the agency thoroughly first, as not all agencies are up to speed on ADA website compliance rules. A qualified web design firm will be able to identify any violations of ADA Website Compliance and outline a plan for updating your online content and properties. 
Any business that is considered a “place of public accommodation” is required to provide equal access to services under the nondiscrimination requirements of Title III of ADA. When you look at the guidelines closely, this includes hotels, entertainment venues, legal and accounting firms, retail stores, and virtually every business that is not a private club, including businesses that exist solely on the web.
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