Main Bearing Clearance

Nope. If the crank is laying on the bearing on the bottom, and you torque the cap, the space left is the clearance.
So if your plasitgage says ".001" because that's how wide it squished and that's what you matched up, you have .001 total clearance, or .0005 per side, and yes that is too tight. You need an undersize bearing for one that is too tight. And oversize bearing for one that is too lose.

If you are measuring you measure the bearing bore top to bottom with the cap torqued, and then the crank journal, and subtract the crank measurement from the bore measurement.

Please answer the question on how you're measuring and was the crank was just turned or used?
this is correct !---------