This plugin allows system administrator to programmatically verify the label assignment correctness on slaves.
Go to the label configuration page of the label whose assignment you want to validate. For example,
You can associate "label verifies" through this UI, as follows:
The script specified here gets executed every time a slave with this label comes online. If the script returns non-zero exit code, the label assignment is considered illegal, and Jenkins will mark the slave as offline to prevent it from getting used for a build.
LabelVerifier is an extension point that can be implemented by other plugins, to perform the check in other means.