Document registry field for MCP server configuration

[Copilot]

The registry field exists in MCP server configuration (implemented in pkg/parser/mcp.go:89, tested in mcp_config_compilation_test.go) but lacked user-facing documentation.

Changes

docs/src/content/docs/reference/tools.md

• Added registry to MCP server options list
• Created "Registry Field" section with purpose, usage guidance, and examples for both stdio and HTTP servers

docs/src/content/docs/reference/mcp-gateway.md

• Added registry to Server Configuration Fields table (Section 4.1.2)
• Added Appendix A.5 with JSON examples demonstrating registry usage

Example

mcp-servers:
  markitdown:
    registry: "https://api.mcp.github.com/v0/servers/microsoft/markitdown"
    command: "npx"
    args: ["-y", "@microsoft/markitdown"]

The field is informational—used for documentation and tooling discovery, does not affect server execution. Applies to both stdio and HTTP transport types.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• telemetry.astro.build
  • Triggering command: /opt/hostedtoolcache/node/24.13.0/x64/bin/node node /home/REDACTED/work/gh-aw/gh-aw/docs/node_modules/.bin/astro build (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

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This section details on the original issue you should resolve

<issue_title>[plan] Document registry field in user-facing documentation</issue_title>
<issue_description>## Objective

Add documentation for the registry MCP property in user-facing guides.

Context

From discussion #11706: The registry field is implemented (pkg/parser/mcp.go:86), tested (mcp_config_compilation_test.go), and compiled correctly, but has NO end-user documentation. Users need to know this field exists and how to use it.

Approach

Add documentation for the registry field to relevant docs:

1. docs/reference/tools.md - Add to MCP configuration reference
2. docs/reference/mcp-gateway.md - Include in MCP server setup examples

Include:

• Field purpose: URI to installation location from MCP registry
• Example usage: registry: "https://api.mcp.github.com/v0/servers/microsoft/markitdown"
• When to use vs other installation methods

Files to Modify

• docs/reference/tools.md - Add registry field documentation
• docs/reference/mcp-gateway.md - Add registry examples

Acceptance Criteria

• registry field documented in tools.md reference
• Example usage included in mcp-gateway.md
• Clear explanation of when to use registry vs other methods
• Consistent with existing documentation style
• Examples tested to ensure correctness

AI generated by Plan Command for discussion #11706

Comments on the Issue (you are @copilot in this section)

• Fixes [plan] Document registry field in user-facing documentation #11710

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[pelikhan]

@copilot simplify docs