First stealth means two things: 1. Reduced Radar Cross Section (RCS) or reflective target as might be detected by primary radars. Primary radars are ones which rely on reflected energy (as opposed to transponders). And, 2. Stealth also implements other passive and active measures. The passive ones include reducing ALL emissions from the aircraft and systems, and the active ones are subtle and may be designed to interfere with various detection techniques. The active measures do not necessarily amount to emitted energy.
So in theory there are not radar signatures of stealth aircraft, at least as common radars go. However, there are many techniques for detecting which are not conventional radar. For example quantum techniques relying on polarization and/or entanglement may be useful where conventional radars fail. Another example is utilization of spread spectrum emissions. Yet another is the use of multistatic radar and processing the signals from multiple sources concurrently received by multiple receivers. Just examples, and there are lots and lots of demonstrated techniques. And countermeasures. Kind of like Spy vs Spy in Mad Magazine.
So when you refer to a radar signature, I assume that you mean the current detection signals of a target at hand. And then the question is can the attributes of that signature be communicated to a fighter that might engage with the initial stealth target. Yes, to a very limited degree. But mostly no, because the detection hardware enhanced detection of stealth aircraft is involved, and not commonly known to exist in common fighter aircraft.
With respect to visual range, it is assumed that when we apply apply the term stealth we are talking of targets which are not visually acquired. Typically they operate at night, or in adverse weather, so that they are not detectable. There are no large scale demonstrated visual stealth, sometimes called cloaking, techniques.
What can readily happen is that ground sensor data from multiple sites can be fused into composite information which is then uplinked to a fighter aircraft. This can be done near real time, but in this example, there is no real detection on the stealth seeking fighter, rather just a situation display utilizing ground sensor and processed data.
There are many more complex answers, and several texts and copious open literature papers are available on this topic. I have just provided a simplified and generalized answer.