CLI: Improve help for cp, mv, thumbs, status, and optimize commands

internal/commands/optimize.go

@@ -14,7 +14,7 @@ import (
 // OptimizeCommand registers the index cli command.
 var OptimizeCommand = cli.Command{
 	Name:   "optimize",
-	Usage:  "Verifies and optimizes metadata",
+	Usage:  "Performs index metadata maintenance",
 	Action: optimizeAction,
 }