[DOCS] Settings docs missing `ENABLE_CLAUDEAI_MCP_SERVERS` opt-out environment variable

Documentation Type

Missing documentation (feature not documented)

Documentation Location

https://code.claude.com/docs/en/settings

Section/Topic

Environment variable reference and MCP server availability controls.

Current Documentation

The environment variable table includes MCP-related entries such as:

ENABLE_TOOL_SEARCH MCP_CLIENT_SECRET MCP_OAUTH_CALLBACK_PORT MCP_TIMEOUT

There is no entry for ENABLE_CLAUDEAI_MCP_SERVERS.

What's Wrong or Missing?

Release v2.1.63 added:

"Added ENABLE_CLAUDEAI_MCP_SERVERS=false env var to opt out from making claude.ai MCP servers available"

This opt-out control is not documented in the settings env var reference or MCP docs, so users cannot discover how to disable claude.ai MCP server availability.

Suggested Improvement

1. Add ENABLE_CLAUDEAI_MCP_SERVERS to the settings environment variable table with:

• Accepted values (false / default behavior)
• Scope (startup/session)
• Interaction with other MCP settings

1. Add a short note in MCP docs explaining how this variable affects claude.ai-provided MCP servers.
2. Include one CLI shell example (export ENABLE_CLAUDEAI_MCP_SERVERS=false).

Impact

High - Prevents users from using a feature

Additional Context

Affected Pages:

| Page | Context |
|------|---------|
| https://code.claude.com/docs/en/settings | Primary environment variable reference is missing ENABLE_CLAUDEAI_MCP_SERVERS |
| https://code.claude.com/docs/en/mcp | MCP behavior/configuration page should cross-reference this opt-out control |
| https://platform.claude.com/docs/en/agent-sdk/mcp | Agent SDK cross-reference for MCP auth/config behavior |

Total scope: 3 pages affected

Related open issue (behavior context): https://github.com/anthropics/claude-code/issues/20412

Source: Claude Code release v2.1.63
Changelog entry: "Added ENABLE_CLAUDEAI_MCP_SERVERS=false env var to opt out from making claude.ai MCP servers available"