{"version":"2.1.319","anchor":"mcp-tool-name-matching-extended-with-namekey-behind-a-check","canonical_anchor":"mcp-tool-name-matching-extended-with-namekey-behind-a-check","heading":"MCP permission rules can match tools by an extra alias name","tier":"internal","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.319\/e\/mcp-tool-name-matching-extended-with-namekey-behind-a-check","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.319","markdown":"### MCP permission rules can match tools by an extra alias name\n\nPermission rules and tool deferral for MCP tools can now also match a tool's alternative name, when an internal check allows it\n\n**Unclear.** It is not stated what turns on the alternative-name matching or what that alternative name looks like for a given tool.\n\n**What**\n\nMCP tools are tools supplied by an MCP server, an add-on that connects Claude Code to outside tools and data. When Claude Code decides whether a permission rule applies to one of these tools, or whether to defer it (hold its full description back until it is needed), it can now also match the tool by an alternative name called `nameKey`. This extra match is used only when an internal check is on.\n\nTool search, the step that loads deferred tools when needed, also now treats a tool as costing nothing when it is marked free and no tools match.\n\n**Why**\n\nThis changes which names a permission rule can catch for an MCP tool, and which MCP tools are held back until needed.\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: no"}