  We consider the chiral Lagrangian for baryon fields with J^P =\frac{1}{2}^+
or J^P =\frac{3}{2}^+ quantum numbers as constructed from QCD with up, down and
strange quarks. The specific class of counter terms that are of chiral order
Q^3 and contribute to meson-baryon interactions at the two-body level is
constructed. Altogether we find 24 terms. In order to pave the way for
realistic applications we establish a set of 22 sum rules for the low-energy
constants as they are implied by QCD in the large-N_c limit. Given such a
constraint there remain only 2 independent unknown parameters that need to be
determined by either Lattice QCD simulations or directly from experimental
cross section measurements. At subleading order we arrive at 5 parameters.
