Usability
Interface 
User-friendliness/complexity of the tool´s interface
Easy-to-use, straightforward.
Time efficiency Time needed for mastering the „how-to“ of the tool and a production of a task
Medium.
Interface language(s) The number of languages in which the tool is currently available/adaptable to
English.
Respect for privacy Does the tool require registration? Who can see my data? Can I remain anonymous?
Medium/high. EclipseCrossword collects and stores data shared by users. It also employs cookies to operate the service, but only for necessary purposes, such as remembering users’ settings, or learning how people use the service in order to improve it. It does not use cookies to track users outside of their services. EclipseCrossword does not share personal information with anyone unless required by law. EclipseCrossword is operated by Green Eclipse in the State of Washington, United States, so regional laws apply. EclipseCrossword does not state compliance with the GDPR. See more here.
Saving work for future use Possiblity to save your or others´ work for reuse/reproduction
Yes.
Tailorability (If so, how?) Possibility of the tool to be used for a range of different activities (e.g. to what extent you can organize a project assignment with a central activity based on this tool)
Limited; users can employ EclipseCrossword only to create crossword puzzles.