Template pools are the entry point to bring structures (or mobs, or features, or …) into the world.

Minecraft pools

The following pools are provided by minecraft automatically.

Villagers

Villagers are provided per biome.

Biome Pool
Plains minecraft:village/plains/villagers
Desert minecraft:village/desert/villagers
Savanna minecraft:village/savanna/villagers
Snowy minecraft:village/snowy/villagers
Taiga minecraft:village/taiga/villagers

These pools give a 10-1-1 chance of providing an unemployed vilager, baby villager, or nitwit.

There are also equivalent zombie villagers:

Biome Pool
Plains minecraft:village/plains/zombie/villagers
Desert minecraft:village/desert/zombie/villagers
Savanna minecraft:village/savanna/zombie/villagers
Snowy minecraft:village/snowy/zombie/villagers
Taiga minecraft:village/taiga/zombie/villagers

These pools give a 10-1 chance of providing an unemployed zombie villager, or nitwit. This is done through the structures minecraft:village/plains/villagers/<name>, with <name> being either baby, unemployed, or nitwit.

Both of these pools require an update-directed jigsaw block to connect to, with the following properties:

Property Value
pool See above
name minecraft:empty
target name minecraft:bottom

Template pools

In my datapack, the following supporting template pools exist.