An IANA Registry for Model Context Protocol Tool Surface Names

This document requests the establishment of an IANA registry for Model Context Protocol [MCP-SPEC] tool surface names. A tool surface name is the wire-level identifier by which a client invokes a typed capability on an MCP server. Existing Morrison- family Internet- Drafts ([ORGALTER]) request IANA registration of specific surface names against a registry that does not yet exist. This document establishes the registry mechanism so that subsequent specifications can register names without restating the registry's structure or registration procedure. The registry uses Specification Required registration with a Designated Expert pool [RFC8126]. Initial contents are the four surface names registered by [ORGALTER]. Vendor-prefix conventions are recommended but not mandated.