Street's confidence after the IPO and concerns about its long-term financial prospects.
Much of Facebook's recent focus has been on making money from users who are migrating to mobile devices. Zuckerberg said he could foresee a business in search over time, but analysts advised caution. Facebook has come under fire numerous times for unclear privacy guidelines.
While Tuesday's revelation fell short of some of the wilder guesses about what Facebook planned to reveal in its highest-profile news briefing since its market debut, analysts said it was overdue for a well-rounded search tool, given its current inadequacies.
Wedbush Securities analyst Michael Pachter argued that recommendations from trusted friends were more valuable than from strangers on the Web.
Facebook has a vast amount of information in its social network, including roughly 200 billion photos. But some analysts noted that the information each user has access to through a network of friends is not always that extensive and could limit the usefulness of Facebook's search offering.
"Very well-connected individuals have a rich treasure trove of data that they can mine, but the average person's storehouse of data is much sparser and has less relevance to these queries," said Ray Valdes, an analyst for Gartner Inc.
Facebook's announcement underscores the increasing overlap between social media and traditional Web search engines. Google, the world's No. 1 search engine, launched the Google+ social network in 2011 and has been integrating data between Google+ into its search engine.
In the works for more than a year, Facebook's new search feature will initially be available for the English language only and for use on desktop PCs.
Bringing the search tool to mobile devices, such as smartphones, would probably require a change in design of the product, noted Valdes. "It might be that they have to come up with innovation like voice search, a Siri-like voice assistant to get it to work well on mobile," he said, referring to the technology available on Apple Inc's iPhone.
Facebook executives at the event showcased a variety of different potential uses of the product, such as finding a date by searching for single men who live in San Francisco and are from India, and creating a holiday card by finding all the photos in which spouses appear together.
The search technology will use the "likes," "check-ins" and star-ratings that Facebook users have posted about restaurants to determine the order of the recommendations displayed, though Facebook search engineering head Lars Rasmussen noted