Most record types use {internalid} or {id}.
I'm not sure whether {recordid} is a valid field ID (maybe?).
Depending on your Suitelet, if you're trying to pass it a transaction, then maybe you're after the {tranid} which is the number in the transaction's name, like Purchase Order #54321, the tranid is the 54321, but this is different from the transaction record's internal ID.
the Internal ID is what you want if your suitelet is using the paramId value to load, edit, or search for, a specific record. Search can also use tranid as a filter just as easily as it can use internalid; it depends on your suitescript code.