AI Agent Validator

i am working on a project where an AI agent generates a graph , the nodes are JSON Structures and each node accepts some sort of input ( google sheet URLs,Email sender ,email receiver ... ) and each node references the next node so that the next node can access the output of the previous step if needed ( we can have loops too ), the problem i am facing is this : i can structure a correct graph (structurally) but the LLM most of the times fails to create the correct refences since it doesn t know how each node should interact with the input of the previous node and can t deal with looping either .i plan to create an execution validator after the build step ,what do you guys recommend ? do i create a validator that does a test run with a test account ( need nearly 600 accounts (gmail , slack,MS .....) or do i make it a graph traversal problem ? i am open to suggestions