Background: For language teachers, using rubrics has become the norm in assessing performance-based work. When using rubrics, one question stakeholders have is to what extent teachers are true to the rubrics. For classroom teachers, the correct use of rubrics is crucial. Rater training and rater calibration are not commonly offered to teacher-raters; therefore, the accurate use of rubrics is required in assessing student performance. Methods: This study investigates the impact of rubric use in assessing short EFL descriptive writing by asking teacher-Q4raters to rate essays, both with and without a rubric. Results: The results show that teachers focused more on errors (e.g., grammar and mechanics) when rating without a rubric, but valued comprehension issues (e.g., main idea, author's voice) when rating with a rubric. Essay scores also increased when teachers assessed with a rubric. Follow-up teacher interviews confirmed that rating changes occurred due to both the assessment criteria in the rubric and the lenient nature of the scale descriptors. Conclusions: For performance-based assessment, rubrics are a central tool that adds reliability, validity, and transparency to assessments. This study shows that experienced teachers-raters were impacted by the content and nature of the rubric's scale, and thus made an effort to follow it.