WordNet sense 1 (an act of narration):

relation, recounting

WordNet sense 2 (informing by words):

notification, apprisal

WordNet sense 3 (disclosing information or giving evidence about another):

singing, tattle

WordNet sense 4 (powerfully persuasive):

cogent, weighty

WordNet sense 5 (disclosing unintentionally):

revealing, telltale

WordNet sense 6 (providing or conveying information):

informative, informatory

WordNet sense 7 (producing a strong effect):

impressive

WordNet sense 8 (producing or capable of producing an intended result or having a striking effect):

effective, effectual, efficacious