---
title: "Glossary: MCP, connectors and agent distribution | Invokary"
description: "Plain definitions of the terms behind getting a SaaS product into AI agents: MCP, connectors, plugins, directories, server.json, tool annotations and evals."
canonical: "https://invokary.com/glossary"
dateModified: "2026-10-05"
---

# Glossary

The terms this site uses, each defined in a sentence or two from the specifications and platform documentation we cite.

- **Agent Distribution Engineering**: Agent Distribution Engineering is the work of making an existing SaaS product listed, working and chosen inside AI agents: tool design, auth, evals, directory submission and measurement after launch.; [What Agent Distribution Engineering covers](https://invokary.com/agent-distribution-engineering)
- **Model Context Protocol (MCP)**: An open protocol that lets AI applications connect to outside tools and data. An MCP server offers tools, resources and prompts; an AI application such as Claude, ChatGPT or Cursor connects to it as an MCP client. The current revision is 2026-07-28.
- **MCP server**: A program that offers tools, resources or prompts to AI applications over MCP. A local server runs on the user's machine and talks over stdio; a remote server runs on the web, talks over Streamable HTTP and serves many users.
- **Connector**: Claude's name for a remote MCP server listed in its Connectors Directory. You submit it as a server URL, and Claude connects to it on each user's behalf.; [Claude Connectors Directory requirements](https://invokary.com/platforms/claude)
- **Plugin**: A packaged extension for an AI product. In ChatGPT, an MCP-backed app listed in the Plugins Directory that ChatGPT and Codex share; in Claude, a bundle hosted on GitHub; in Cursor, a Git repository with a plugin manifest.
- **Claude Connectors Directory**: Anthropic's directory of MCP connectors. Submissions go through the directory submission portal, automated checks and a safety scan. New listings carry the Community label, and Anthropic may escalate a connector to Verified review on its own.; [Every requirement, with sources](https://invokary.com/platforms/claude)
- **ChatGPT Plugins Directory**: OpenAI's directory of plugins, shared by ChatGPT and Codex. A submission needs a verified identity, a domain verification token, exactly five positive and three negative test cases, a demo recording and release notes.; [Every requirement, with sources](https://invokary.com/platforms/chatgpt)
- **Cursor Marketplace**: Cursor's directory of plugins. Plugins are submitted from a public Git repository at cursor.com/marketplace/publish and reviewed by hand before they are listed.; [Every requirement, with sources](https://invokary.com/platforms/cursor)
- **Official MCP Registry**: The MCP project's public registry of MCP servers, still in preview. Each entry is published from a server.json, under a namespace the publisher authenticates through GitHub, DNS or HTTP.; [Every requirement, with sources](https://invokary.com/platforms/mcp-registry)
- **server.json**: The file that describes an MCP server to the Official MCP Registry: its name, its version and, for a remote server, the URL listed in its remotes property.; [The registry's server.json rule](https://invokary.com/platforms/mcp-registry#mcp-registry.server-json)
- **Tool annotations**: Hints a tool declares about its behavior: readOnlyHint, destructiveHint, idempotentHint and openWorldHint. The MCP spec tells clients to treat them as untrusted unless the server is trusted, and Claude's and ChatGPT's reviewers check them.; [Claude's annotation rule](https://invokary.com/platforms/claude#claude.rule-annotations)
- **server/discover**: The request every MCP server must answer under the 2026-07-28 revision, giving the protocol versions, capabilities and identity it supports. That revision removed the initialize handshake, which older clients still send.; [Moving a server to the current spec](https://invokary.com/services/connector-upgrade)
- **Client ID Metadata Document**: An HTTPS URL that an MCP client uses as its OAuth client ID. The URL serves a JSON document describing the client, which the authorization server fetches and checks, so the two need no prior registration.
- **Dynamic Client Registration (DCR)**: An OAuth standard (RFC 7591) that lets a client register itself with an authorization server. MCP 2026-07-28 deprecates it in favor of Client ID Metadata Documents and keeps it for backward compatibility.
- **Evals**: Automated tests that give an AI agent connected to your server realistic prompts and check that it picks the right tool and gets a correct result.