Be particularly careful with wok ingredients that are very very moist and have a great deal of water in them. A good example of this is a very young mushroom which may be mostly water by weight. Such mushrooms typically are slow to begin cooking as they have not yet released the water in their cell structure, however as soon as they get hot enough that they are cooking and the cells and tissue are breaking down - all that water will come out into your wok. If you have a lot of ingredients like this, you can rapidly have your wok recipe turn into a wok soup, and then you will not get things searing as you would like and things may end up cooking too long as you try to cook off the water.
However, because steam is the primary element imparting heat when the wok lid is on the wok, you may have to add water initially to kick start the cooking process - even if the food items are going to release a lot of moisture as they cook. Be as sparing as possible in circumstances like these with any water you add to the wok - knowing that there is lots of it waiting to come out as soon as cooking starts. You may want to add little or not additional water and instead stir and turn the ingredients uncovered for a longer period to get the water to start coming out which will then create steam in the wok without you having to add any additional water to the wok.