"stringent constraints" is a correct and usable phrase in written English.
You can use it to refer to the imposition of severe restrictions or limitations. For example, "The company enforced stringent constraints on employees' ability to take sick days."
This measurement provides new stringent constraints for parton distribution functions.
The anatomical structures within the organ of Corti clearly impose stringent constraints on the motion.
The most stringent constraints on wino dark matter come from astrophysical searches for its annihilation products.
Lower bounds on the Phi mass are reported, providing significantly more stringent constraints than previously published limits.
Their software components should run on platforms with stringent constraints on node resources.
This has set some stringent constraints on the design and construction of the SPD.
Both measurements are statistically compatible with standard model predictions and allow stringent constraints to be placed on theories beyond the standard model.
The latest experiments using precision spectroscopy of diatomic molecules provides more stringent constraints on the masses of new particles than the Large Hadron Collider.
New data from NASA's Chandra X-ray Observatory has provided stringent constraints on the environment around one of the closest supernovas discovered in decades.
The coincidence data set stringent constraints on theoretical models that were introduced to interpret the peak shift in inclusive spectra.
After a day of nonstop negotiations and meetings, Republican strategists said party leaders would make several attempts to try to scuttle the Shays-Meehan bill to ban soft money by proposing even more stringent constraints on political donations.
