# How do we know Solow has DRS and Harrod-Domar has CRS from the definitions of the models?

This may be a stupid questions as I am just studying undergrad economics honours but how do we know that the solow model has diminishing returns to its input and harrod-domar has constant returns to its inputs from the definitions of the models? Like for example if in the harrod domar model, we take Y to be a function that has diminishing returns to scale then how can we say that it always has CRS?

For example, if $$F(K,L)=AK^{0.5}L^{0.5}$$ then we know it will always have constant returns to scale since when you increase both factors $$K$$ or $$L$$ by some scalar $$z$$ output also increases by $$z$$.
$$F(zK,zL) = A(zK)^{0.5}(zK)^{0.5}=z AK^{0.5}L^{0.5} = zF(K,L)$$