Final answer:
One characteristic of case tools for the requirements workflow is that the documentation is always stored in the tool.
Step-by-step explanation:
One characteristic of case tools for the requirements workflow is that the documentation is always stored in the tool. Case tools, such as software development environments or project management tools, are designed to assist in the analysis, design, implementation, and testing of software systems. Storing the documentation within the tool allows for easy access and collaboration among team members.