{"version":"2.1.323","anchor":"mcp-tool-schema-file-upload-marking-supports-anyofoneof-bra","canonical_anchor":"mcp-tool-schema-file-upload-marking-supports-anyofoneof-bra","heading":"MCP file arguments are recognised in more kinds of tool definitions","tier":"notice","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.323\/e\/mcp-tool-schema-file-upload-marking-supports-anyofoneof-bra","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.323","markdown":"### MCP file arguments are recognised in more kinds of tool definitions\n\nClaude Code now spots file arguments in more MCP tool definitions, including ones that offer a choice of forms\n\n**What**\n\nAn MCP tool is a tool from an outside program you connected. Each tool describes the arguments it takes. Claude Code looks through that description for arguments that are files and changes how they are shown to Claude.\n\nBefore, it only recognised a single file, an optional file, or a list of files. It now also handles:\n\n- Arguments that can take one of several forms\n\n- Forms that allow an empty value\n\n- File entries given only by a fingerprint, with no file name\n\nThe parts it recognises are hidden or listed, and the argument's description is rewritten. Claude Code works this out once per tool definition and reuses it.\n\n**Why**\n\nFor MCP tools with these more complex argument descriptions, file arguments now look different to Claude.\n\n- Area: MCP\n- Tier: You'll notice\n- Useful: 1\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}