External Tool
10: External Tool

Many websites provide materials and interactive learning exercises different from and complementary to Moodle’s own resources and activities. The external tool offers a way for teachers to link to these activities from within their Moodle course page and where available to have grades sent back into Moodle. Students only need to log in to Moodle; they do not have to log in a second time to the connecting site.
Sites which allow connection to Moodle in this way are known as LTI compliant and are called Tool providers. The “tools” are the exercises or materials which Moodle can connect to.
The External tool enables participants to interact with LTI-compliant learning resources and activities on other web sites. (LTI is an IMS standard for Learning Tool Interoperability.) For example, an external tool could provide access to a new activity type or learning materials from a publisher.
Brightspace
Learning Tools Interoperability (LTI) is a proposed standard for passing user, organization, and course information between learning management systems (platforms) and learning tools and tool providers, such as wikis, simulations, assessment tools, protected content, and so on.
Brightspace Learning Environment supports LTI 1.0, 1.1, 1.1.2 and 1.3 (LTI Advantage).
Bottom line
External Tools are configured by the administrators on the site generally and then used by the Instructors or teachers. While Brightspace supports the latest versions of LTI, it should be noted that not all the plugins from the publishers are using the latest version of the LTI. This in turn leads to limited functionality and lack of functionality between systems. Hopefully, this will be resolved in the future.