# Amazon — Discover tools at runtime with AWS Agent Registry

- Company: Amazon (amazon.com)
- Announced: 2026-10-20T16:22:24+00:00
- Category: developer-tool-release
- Coverage: not counted
- Announcement: yes
- Group: announcements
- Source: https://aws.amazon.com/blogs/machine-learning/discover-tools-at-runtime-with-aws-agent-registry/
- Record: https://forck.live/items/25303-discover-tools-at-runtime-with-aws-agent-registry
- Subject: Bedrock / Nova

AWS has introduced Agent Registry, a managed service for cataloging and discovering Model Context Protocol servers, agents and agent skills, so orchestrators can find tools at runtime instead of hardcoding them. The post argues that hardcoded tools work for a handful but degrade at a few dozen and become unmanageable beyond that, as enterprise systems expose hundreds of internal APIs for pricing, support, orders, inventory and customer data. Publishers register protocol-specific descriptors and searchable descriptions, and an orchestrator can search approved, discoverable records and use the returned endpoint and descriptor content to construct a client. Registry search results do not return the capability's invocation credentials or authentication scheme, so the application must obtain and apply credentials through a separate, trusted configuration path. A refactored Python sample demonstrates a Discover, Instantiate, Execute loop that deploys an order-management MCP server through Amazon Bedrock AgentCore Gateway, two agent-to-agent agents on AgentCore runtime, a Registry and an orchestrator. An ephemeral inner agent is built with only the dynamically discovered tools, and after the turn finishes the inner agent and its clients are torn down, so the next request gets a fresh search and a fresh tool set. Three demo scenarios exercise the loop: an MCP-only order status call, a chained MCP and A2A pricing and discounts call, and a semantic match for return and refund where those words do not appear in the matched agent's name.

## Evidence

Verbatim from https://aws.amazon.com/blogs/machine-learning/discover-tools-at-runtime-with-aws-agent-registry/:

> AWS Agent Registry is a managed service for cataloging and discovering Model Context Protocol (MCP) servers, agents, and agent skills. Publishers register protocol-specific descriptors and searchable descriptions. At runtime, an orchestrator can search approved, discoverable records and use the returned endpoint and descriptor content to construct a client.

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Record: https://forck.live/items/25303-discover-tools-at-runtime-with-aws-agent-registry
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