{"version":"2.1.321","anchor":"mcp-admission-and-reserved-address-classification","canonical_anchor":"mcp-admission-and-reserved-address-classification","heading":"Stricter policy checks before MCP servers are reused or refreshed","tier":"notice","area":"MCP","scope":"both","heads_up":true,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.321\/e\/mcp-admission-and-reserved-address-classification","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.321","markdown":"### Stricter policy checks before MCP servers are reused or refreshed\n\nClaude Code now rechecks SDK MCP servers against policy before reuse, refreshes tools only for allowed servers, and sorts private addresses by type\n\n**Unclear.** Which servers the new checks would turn away, and what you would see when that happens, is not stated.\n\n**What**\n\nMCP servers are connections that give Claude extra tools. Claude Code now checks them more strictly:\n\n- SDK servers (ones supplied by the program driving Claude Code) are checked against policy again before they are reused.\n\n- When reconnecting, Claude Code only fetches the tool list again for servers that pass an admission check.\n\n- The check for private network addresses now says what kind of address it is, such as `link_local` or `carrier_nat`, instead of a plain yes or no.\n\n**Why**\n\nPolicy on which MCP servers may be used is enforced in more places.\n\n- Area: MCP\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 1\/5\n- Scope: both\n- Heads-up: yes"}