MCP connectors vs. custom tools
The Model Context Protocol (MCP) is an open protocol that lets an AI assistant like Claude connect to external data sources and tools through a standardized server interface, instead of every integration being bespoke. An MCP server exposes a set of tools -- and sometimes resources or prompts -- over a defined transport (for example stdio or HTTP), and any MCP-compatible client can connect to it using the same protocol.
Connectors
A "connector" is typically a pre-built, ready-to-use integration -- often maintained by Anthropic or a third party -- that wraps an MCP server for a specific external product, so a user can enable it from a settings UI without writing any code. Common examples people use with Claude include connectors for Google Drive, Slack, Asana, Linear, Atlassian (Jira/Confluence), GitHub, and Notion, among others. Exact product names, parameters, and availability can change over time and vary by plan/product, so this site deliberately keeps these descriptions general rather than asserting specific version numbers.
Custom tools
A "custom tool" is a tool an application or developer defines and registers directly -- for example, in the Managed Agents API, or via a hand-written MCP server -- rather than through a pre-built connector UI. Custom tools can be scoped to exactly the actions an application wants to allow, and (per this family's own subagentpermissions.com) are not necessarily governed by the same permission-policy mechanism that governs the built-in agent/MCP toolsets -- the application deciding to expose the tool is responsible for its own access control.
Where this repo sits
This repo uses both: pre-built connectors are not central to its own workflow, but it runs several of its own custom MCP servers (crates/engineering-coworker, plus filesystem/Cloudflare/Postgres MCPs wired into Claude Desktop profiles) and also connects to a curated catalog of MCP servers via Docker Desktop's MCP Toolkit. See the Docker Toolkit pattern page for the real, dogfooded example.
General MCP/connector description from own knowledge; no specific version numbers or release dates asserted where not independently verified this session.