AWS Launches ToolSimulator — LLM-Powered Tool Simulation Framework for Testing AI Agents at Scale Without Live API Calls

AWS Machine Learning Blog·medium signal

AWS released ToolSimulator within its Strands Evals framework, an LLM-powered tool simulation system that automatically infers tool behavior from schema and docstrings. Instead of risking live API calls that expose PII or trigger unintended actions, or using static mocks that break with multi-turn workflows, ToolSimulator generates realistic tool responses for integration testing. Supports shared state across tools via share_state_id parameter. Available via pip as part of the Strands Evals SDK.