What is Intelligence? Is it based on prediction capability of an agent? I have the intuition that at a first level is the capability of an individual to predict outcomes of her/his/its own actions in a environment were he/she/it has familiarity with (don't you feel stupid when you find yourself stranded in unknown environment?).

Then at higher level intelligence should correspond to be able to predict the outcomes of the actions of the other agents in the same environment, especially if they have a significant impact on the subject autonomy.

Does my intuition make sense?
There is no agreement among scholars about what intelligence might be. You must keep in mind that we cannot directly see intelligence. We don't even know if it actually exists! The idea of intelligence was invented to describe what we think might be the cause of certain observable behaviors, but there are others who think that we are throwing together disparate things in one pot that are caused by a whole variety of different powers.

Think of it like you think of love. Does anyone really love anyone? Or do we only follow a bunch of emotions like sexual attraction, fear of being alone, and so on? And even if there is "true love", what is it? Is it the love of a mother for her child? The love of a person for his job? The love of a teenager for an unattainable celebrity?

Similar confusion and doubts pertain to the concept of intelligence. Is there such a thing as a unified intelligence? Or is it made up of a set of partial intelligences (verbal intelligence, mathematical intelligence, spacial intelligence, and so on)? Or is there no "intelligence" at all and only things like memory capacity, processing speed and so on? And even if there were such a thing as general intelligence, is it the actual current ability to solve a problem, or the level of the most difficult problem you could potentially solve if you were trained to your maximum? Is it the ability to find a solution fast, or to find the best solution?

Psychology tries to avoid the pitfalls of these concepts and rather investigates the observable behavior itself: e.g. mate choice in the case of love, or problem solving behavior in the case of intelligence. Because that way we can all agree on what we are talking about, and it can be measured and quantified and interventions can be planned.

Intelligence is not a really useful concept.