If it's in green (i.e., at least 21), there are enough houses for golems to spawn in the village (doesn't mean that there are enough villagers though). If you're inside the golem spawn zone, an extra line will appear. The one in bracket stands for the limit (determined by number of villagers). Note that there's some oddity in the way Minecraft counts villagers (which is different than the method used to find a village for a specific villager), because it counts villagers using a box with only 9 height, instead of a sphere. The number in brackets stands for the breeding limit (determined by number of houses). The radius is determined by the largest distance from the center to a house. Center and Radius The center of the village is determined by the average coordinates of the houses (i.e., it sums up all coordinates and divides them by the number of houses). 'Distant village found' means it found a village more than 32m away. If you're close to one (<32m away), it'll say 'Nearby village found'. If you're inside a village, it will say 'Inside village'.

Finding a Village The mod automatically scans for villages close to you. The output can be found below your coordinates. To activate the mod, press F3 in a single player game. However, I thought it might help people to better understand the mechanics of villages. For technical reasons, it only works in single player. It also tells you if there's a village nearby. This mod shows some information about the village you're currently in.

Modded minecraft launcher