Claude Code 2.1.299 changed which MCP server an allow rule reaches. Check your name.
By Lior AharonovFounder, 7IT Solutions ·
Claude Code 2.1.299 is the latest release. Its changelog says an MCP allow rule now reaches only the server it names, so mcp__a no longer allows a server named a__b or a_. Deny and ask rules for server names that contain __ are fixed too, and agent tools lists follow the same exact-name rule.
Picture a user's rule for server a. It no longer quietly covers a__b or a_. If your server name contains __ or starts with another server's name, a short rule may stop reaching you, and the permission prompts come back.
Check whether your server name contains __. If it does, tell users to write mcp__<server>__* with the whole normalized name, or rename the server.
A server name is part of your permission surface. Pick one that cannot be confused with a prefix of another.
Lior Aharonov · my takeSources
- Claude Code changelog, version 2.1.299 raw.githubusercontent.com
- npm registry: @anthropic-ai/claude-code latest registry.npmjs.org
Researched with AI tools; every fact is checked against the linked sources.