Amazon SageMaker Ground Truth is designed to support human evaluation and labeling workflows using both internal teams and external workforces. AWS documentation states that Ground Truth enables organizations to build high-quality labeled datasets and conduct human reviews using private workforces, vendor-managed workforces, or third-party providers.

In this scenario, the company needs to evaluate toxicity in foundation model outputs, which requires nuanced human judgment. AWS highlights that Ground Truth supports tasks such as content moderation, sentiment analysis, and safety evaluation, making it well suited for assessing harmful or toxic content generated by models.

Ground Truth provides managed tooling for task distribution, reviewer instructions, quality control, and auditability. It allows companies to seamlessly scale operations by combining internal reviewers for sensitive data with external reviewers for higher-volume workloads, while maintaining consistent review standards.

The other options do not meet the requirement. Amazon Bedrock Agents orchestrate interactions with foundation models but do not manage human review workflows. Amazon Comprehend Custom focuses on training NLP models, not evaluating FM outputs. Amazon SageMaker JumpStart provides pretrained models and solutions, not human evaluation pipelines.

AWS positions SageMaker Ground Truth as a core service for human-in-the-loop machine learning and responsible AI, making it the correct choice for toxicity evaluation using both internal and external reviewers.