How do you judge intraprocedural whether an EBUS-TBNA sample is adequate for molecular testing?

When you get your TBNA sample during the procedure, what cues make you think "this might not be enough for EGFR/ALK/PD-L1 testing"? Is it the ROSE wording, the visible aspirate volume, or some other experience-based judgment? Just trying to gather how people actually make this call in practice.