I'm curious about the `license` field in the specification: https://agentskills.io/specification https://agentskills.io/specification. Could one make a copylef

I'm curious about the `license` field in the specification: https://agentskills.io/specification https://agentskills.io/specification. Could one make a copyleft type license such that the generated code must be licensed free and open and under the same license? How enforceable are licenses on these skills anyway, if one can take in the whole skill with an agent and generate a legally distinct but functionally close variant?