Do you mean "technical precision" using the R-squared value for the best-fit line of linear regression?

Or do you mean "minimal detectable template" from your standard curve?

Or do you mean "primer specificity to target sequence"?

There is no single definition of precision of precision in RT-qPCR. It depends on numerous factors- e.g.

Absolute vs Relative quantification

No. of technical and biological replicates and variation between them (SD or SEM)

The efficiency of RT-qPCR reaction

Assay LDR etc....

Of course, you can enhance system precision, thereby improving the accuracy of experimental variation as a reflection of biological diversity.