Mass is on a log scale. The 0-100% range maps on to 0.1 to 10 times the mass of the sun (50% = 1 solar mass).
Eccentricity for the planetesimals is from 0 (circular) to 100% (parabolic), via flavours of elliptical.
Alternatively, there is a Java implementation available as a Jar file, containing source as well as the class files. The jar can be used as a free-standing java application, invoked by
java -cp acrete.jar acrete.Main