Across a variety of assignment and activity types, it pays to be transparent about purpose, operation and criteria. The Transparency in Teaching and Learning (TILT) framework provides a helpful guide to assignment or assessment design:
This assignment has them students skills they will need "out in the world," such as medical procedures in a healthcare job, or accounting functions for managing an enterprise's budget and spending.
This reading reflection walks students through the steps of reading critically, as a professional does. This is explicitly compared to just reading, as they might, an adventure novel for pleasure or a social medai post to pass the time while waiting in line.
This quiz requires students to demonstrate working knowledge of important information - yes, memorization sometimes matters! - by applying it to describe or prescribe a particular situation or solution. This could be vocational information: how to perform a calculation for interest on a business loan. Or, it could be for community engagement: perform a calculation to understand how fluctuations in a local housing market impact the lives of refugees.
This should be explicit, describing what steps students should take to complete the assignment. A big exception to that is when the assignment is assessing how students choose or develop a list of steps to complete a task. Then, be explicit about that:
for this assignment, students will need to develop a plan to complete the assignment, based on learning done previously in the course.
if the assignment feels like a challenge and prompts moments of discomfort, that is by design since applying their skills and developing confidence are goals of the assignment!
What factors should students bear in mind as they complete the work? "Criteria" is a common term used for rows in a rubric, and can otherwise be presented to students as the basis for their grade. Meshed with the procedure above, presenting a detailed list of criteria helps students prioritize, stay on course toward what's important, and not lose time or focus speculating as to what they should be doing.
To prompt students to think more deeply about an assignment, you might ask them to help you draft criteria. This could be the basis for a classroom or asynchronous message board discussion. Working as a class group or in small groups, students might draw from course content, or be required to review sample "A" submissions, and then work together to develop a list of criteria.
Additional resources on transparency in pedagogy can be found at the TILT Website.