There is a statutory obligation to file an Affidavit of Means, discovery will generally be sought in family law matters where it is considered that there are defects or omissions.
There are time limts.
Also in Ak v PK [2005] IEHC 331 an unsigned undated list requiring 34 items - the Master said "No relevance, no reason, no necessity - no discovery' i.e. no fishing trips.
[Extract Consolidated Circuit Court Rules]
Does that help