Annotating wireframes, just like wireframing itself, is an iterative process. As a rule of thumb, your notes will get more detailed as the fidelity increases.

For example, you might start with a couple of comments about your thought process on a paper sketch. As you move into digital tools, your annotations will become more elaborate. After talking with developers, you might add more technical information.

Here are some suggestions about what you need to concentrate on at different fidelity levels:

• In sketches, add comments on ideas, personas, and scenarios.
• In low-fidelity wireframes, concentrate on initial design decisions and explore various UI options.
• In medium-fidelity wireframes, describe the functionality and layout reasoning.
• In high-fidelity wireframes, detail in-depth functionality, content and design decisions, and scenario rationale.