In American Transitional Care Centers of Texas, Inc. v. Palacios, 46 S.W.3d 873, 877, 44 Tex. Sup. Ct. J. 720 (Tex. 2001), the Court held that a trial court's decision to dismiss a case under section 13.01(e) was reviewed for abuse of discretion. 46 S.W.3d at 875. The Court based our holding on the statute's plain language, which vested the trial court with discretion, and the fact that dismissals under section 13 were in the nature of sanctions, for which an abuse of discretion standard of review was appropriate. 46 S.W.3d at 877 (noting that section 13.01(l) directed the trial court to grant a motion challenging the adequacy of an expert report if it "appeared to the court" that the plaintiffs did not make a good-faith effort to meet the statutory requirements). The Court explained that, when considering a motion to dismiss under section 13.01(l), "the issue for the trial court is whether 'the report' represents a good-faith effort to comply with the statutory definition of an expert report." Palacios, 46 S.W.3d at 878. To constitute a "good-faith effort," the report must provide enough information to fulfill two purposes: (1) it must inform the defendant of the specific conduct the plaintiff has called into question; (2) it must provide a basis for the trial court to conclude that the claims have merit. Palacios, 46 S.W.3d at 879. The trial court should look no further than the report itself, because all the information relevant to the inquiry is contained within the document's four corners. Palacios, 46 S.W.3d at 878. The report need not marshal all the plaintiff's proof, but it must include the expert's opinion on each of the three elements that the Act identifies: standard of care, breach, and causal relationship. Palacios, 46 S.W.3d at 878. A report cannot merely state the expert's conclusions about these elements. Palacios, 46 S.W.3d at 879.