Usability
Interface 
User-friendliness/complexity of the tool´s interface
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. Crossword Labs collects user data relevant to providing its crossword creation and solving services. It works with third parties but prevents unauthorised access or misuse of data, does not run ads, and does not share user data for marketing purposes. Data is stored in the United States. CrosswordLabs explicitly states that individuals under 13 years of age are not authorized to register on the site. It does not mention compliance with the GDPR. See more here.
Saving work for future use Possiblity to save your or others´ work for reuse/reproduction
Yes, but case-specific password is needed.
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)
Yes, users can create crosswords from scratch and in any language