Question Observation of other agents' information in multi-agent

I want to know when I use the information of other agents in the received information of agent 0, is its information observable everywhere? If yes, how to observe this information when agent 1 is within a specified distance from agent 0?

Code (CSharp):

1.     public override void CollectObservations(VectorSensor sensor)
2.     {
3.  
4.     if (transform.position == area.AgentsList[0].Agent.transform.position)
5.             {
6.                 sensor.AddObservation(transform.InverseTransformDirection(area.AgentsList[1].Rb.velocity));
7. }
8. }