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.
Web developers need to keep this in mind when creating websites. The best screen readers use naturalized voices and alter tone and inflection based on HTML tags, so choose layout elements carefully. It is also important to keep in mind that navigation is significantly slower when using a screen reader than it is for sighted people. Sighted people don't have to wait for the reader to get to the link we want- we spot links quickly and are able to navigate to our sought items, often without having to do any reading at all. Minimizing graphics also helps shorten reading times and speed navigation for disabled users.
Maybe just like you, at first we didn't have a darn clue about how to build a website, nevermind write half a line of code if our life depended on it! We wanted to build a website to start a side business, and felt overwhelmed, confused & scared about how to actually do it, which builder to use, and making wrong decisions. After years of trials & errors using different website builders, we're here to share our experiences with you.
Talk to your web designer about other techniques that will make your site more user-friendly for people with disabilities. Worried that’s not in your budget? Consider the fact that DOJ fines start at $75,000. And it's still yet to be determined if a non-compliant website is liable for one fine or will be charge per page for each violation. As the recent lawsuits illustrate, though, settlements quickly add up into the millions.