Improved DocString

lm_eval/api/metrics.py

@@ -271,6 +271,7 @@ def ter(items):
 @register_metric(metric="toxicity_perspective_api", higher_is_better=False, aggregation="mean")
 def toxicity_perspective_api(items):
     """Toxicity Perspective API is a metric which uses Perspective API to score the toxicity of a generated sentence.
+    Scores above and including 0.5 are considered toxic based on the current practice in existing literature.
     Source: https://perspectiveapi.com/
     
     Lower is better