What changed
AWS made Web Answer generally available as a managed AgentCore Gateway tool. One MCP call returns a synthesized answer with source URLs from an Amazon-operated web index, supports domain and date filters, publishes CloudWatch metrics and costs $10 per 1,000 calls.
Why it matters
Teams can replace a custom search, retrieval, synthesis and citation pipeline with one governed service call, but they also surrender ranking, retrieval and synthesis control to a managed component whose citations still require claim-level review.
What to do
Run a canary against a fixed set of time-sensitive questions, compare its citations and omissions with your existing retrieval stack, set narrow domain bounds, log structured citations and retain a fallback path for raw search results or insufficient evidence.
Caveat
Web Answer is initially limited to us-east-1 and a 10-transaction-per-second account limit. AWS describes responsible-AI safeguards and zero data egress, but answer quality and citation support still need workload testing; use Web Search when raw results or custom synthesis matter.