Page titles and URLs can be too long for usability purposes, as can page descriptions, and packing too many links on a page can also be bad for usability (in addition to being a sign of a link farm, affiliate marketing spam site, or other spammy/low-quality sites).
So this gives search engines plenty of reasons to penalize, or at least not favor, sites for having too long a page title/description/URL or too many links. As far as how much affect this has on ranking, it's probably not that significant unless you have so many links or such suspicious-looking URLs and page titles (not just in length but content as well) that you're flagged as a potential spam site.
I'm not sure there are any published hard limits on these items, but if you use a little common sense and stay within reasonable limits, you shouldn't have anything to worry about. At the end of the day, if you concentrate on user experience, these sort of ranking factors will sort themselves out.
It also doesn't make sense to have a hard limit on something like link count, as what's a reasonable range may be different from one page to another. It depends on the type of page it is as well as the length/amount of content on the page. If one page is 1 printed page long, and another is 50 printed pages long, then the second page is probably going to naturally contain more links. Likewise, certain types of pages have legitimate reasons for containing lots of links:
- a directory/glossary/index page
- a search results page
- a rich AJAX interface
- an RSS feed
These types of pages are common enough that most search engines probably know to make exceptions for pages with a legitimate need for a high number of links. So just think about what would be best for your users. If dumping 50 links on a single page is potentially confusing to users, then redesign your navigation flow to improve UX, regardless of whether Google/Bing/etc. will reward you for it.
The same is true with meta descriptions. These are frequently used by web browsers, accessibility software, and other desktop and web apps that handle or process links & webpages, e.g. newsfeed generators, social bookmarking sites like del.icio.us, link sharing sites such as Facebook, Google+, etc., in addition to search engines and web directories. So when determining the length of your page description, take into account how it will be displayed in such applications.