Almost any browser addon/extension that I install on my Chrome or Firefox (be it Firebug, RESTClient, ...) warns me, saying:

It [the add-on] can:

• Access your data on all website
• Access your tabs and browsing activity

Now, practically speaking, I have no time (or the skill) to read through their source-code and verify absence of malware (such as one placed in by its original author).

Given this, can I safely assume these add-ons won't violate my privacy because they are coming from standard/well-known and thus implicitly trusted places, such as the Chrome Web Store, the Firefox add-on site, or the EFF site.

Even an add-on like HTTPS Everywhere, which you install to maintain privacy and prevent MiTM attacks, warns similarly.

Is there any way to quickly tell what add-on to install and what not to, without having to read their source code?