Tool Registry
A catalog of available tools, APIs, and integrations that an AI agent can discover and use. Instead of hardcoding tool connections, a tool registry lets agents dynamically find the right tool for a task—similar to how MCP (Model Context Protocol) standardizes tool discovery. Tool registries describe each tool's capabilities, input/output schemas, authentication requirements, and usage limits, enabling agents to select and invoke tools intelligently.
Written by Max Zeshut
Founder at Agentmelt · Last updated Sep 9, 2026
Example
An operations agent needs to look up a customer's subscription status. It queries the tool registry, finds three options: Stripe API (billing data), HubSpot CRM (account data), and the internal admin API (full customer record). The agent selects the Stripe API because the task only requires billing information and Stripe returns the fastest response.
Frequently asked questions
- How does a tool registry relate to MCP?
- MCP (Model Context Protocol) is a standardized implementation of the tool registry concept. It defines how tools describe themselves and how agents discover and invoke them. A tool registry can be proprietary (built into your agent platform) or standards-based (MCP). The trend is toward MCP compatibility, which allows agents to connect to any MCP-compliant tool without custom integration code.