Start by recording the S-parameter file revision, device ordering code, bias, temperature, frequency grid, reference impedance and measurement plane. State whether package, bond wire, PCB launch or fixture is included. Keep small-signal S-parameters separate from noise, nonlinear, load-pull and thermal models; each answers a different question and has its own validity range.
Evaluate stability over the intended and credible source and load reflection coefficients, out-of-band terminations, bias-network resonances, control states, startup and shutdown, temperature and board parasitics. K and delta, mu factors and stability circles can identify risk, but the metric must match the network and condition. Include large-signal or time-domain work when compression, switching or nonlinear feedback can change the result.
Verify the final matching, grounding and bias layout with representative mismatch and supply conditions. Characterize or remove the fixture at declared planes, preserve raw and corrected data, and record frequency, power, bias, temperature and uncertainty. A stable evaluation board or a nominal K greater than one is evidence for that configuration, not universal proof for every installation.