Braintrust vs Google Cloud Agent Evaluation

Braintrust is an observability platform for teams running AI agents in production. It lets teams inspect agent traces and tool calls while tracking latency, cost, and quality in real time. Users can evaluate datasets, compare prompts and models, and score outputs with LLMs, code, or human reviewers. Discovery tools surface patterns in production traces to help investigate agent behavior, and the Loop agent can run evaluations, generate test cases, and iterate on prompts autonomously. Braintrust lists native SDKs for Python, TypeScript, Go, Ruby, C#, and more, and its MCP server lets coding agents query logs, run evaluations, and update prompts from an IDE. Security options listed include SSO, RBAC, and hybrid deployment; Braintrust states that it is SOC 2 Type II certified and GDPR and HIPAA compliant. Starter is free, with 1 GB processed data, 10,000 scores, and 14-day retention. Pro costs $249.00 per month; Enterprise pricing is custom.

Google Cloud Agent Evaluation helps measure and improve agent performance, safety, and quality. Its workflow runs from defining evaluation cases through inference, behavior-trace capture, metric calculation, result analysis, and optimization. It can generate varied, multi-turn test scenarios from agent instructions and tool definitions, and intercept tool calls to supply custom behavior, mocked data, or simulated errors such as HTTP 503 responses and latency spikes. Prebuilt or custom raters score traces with reference-based Exact Match or reference-free Helpfulness metrics. Teams can also evaluate production-traffic traces or external logs without a managed test environment. Prompt optimization identifies failure points and proposes focused system-instruction changes. The service supports tool-call checks, safety evaluations, regression runs, trace ingestion, and custom models. Access is through API or web, with notebook launch options for Colab, Colab Enterprise, Agent Platform Workbench, and GitHub. Pricing is usage-based: $0.00003 per 1k input characters and $0.00009 per 1k output characters for computation-based metrics; model-based metrics also incur underlying autorater model costs. New Google Cloud customers get $300 in trial credits.