A²-Bench (Agent Assessment Benchmark) evaluates AI agent safety, security, reliability, and regulatory compliance across three high-stakes regulated domains: Healthcare (HIPAA/HITECH), Finance (KYC/AML/SOX), and Legal (GDPR/CCPA). Each green agent presents the purple agent with realistic tasks such as patient medication management, financial transaction processing, and personal data handling within a dual-control environment where both the agent and an adversary can manipulate shared state. Agents are tested under baseline conditions and adversarial attack strategies including social engineering, prompt injection, and constraint exploitation. Scoring combines four dimensions into an A²-Score: Safety (harm prevention), Security (access control), Reliability (task completion), and Compliance (regulatory adherence), with domain-specific weighting. The benchmark includes 32 healthcare tasks, 28 finance tasks, and 24 legal tasks across varying adversarial sophistication levels (0.3–0.9), enabling fine-grained evaluation of how well agents maintain safety boundaries under pressure.