Root and declaration protocolVersions arrays are non-empty, contain no duplicates, and name only MCP protocol versions this specification supports.
Requirement
Section titled “Requirement”A protocolVersions array is non-empty, has unique values, and contains only supported MCP protocol-version identifiers.
Details
Section titled “Details”Rule ID: mcpdesc.protocol-versions.values
Owner: mcpdesc
Surface: Document, scoped declarations
Kind: structural
Requirement level: must
Protocol versions: independent of the MCP protocol version
Document schema locations: #/$defs/protocolVersionScope, #/$defs/supportedProtocolVersion
Status: internal · Enforcement: internal
Required by
Section titled “Required by”- MCP Description 0.9.0, Section 4
- 4. Versioning: req-protocol-versions-values
Examples
Section titled “Examples”Invalid example
Section titled “Invalid example”Source: expected-invalid/closed-protocol-enum.json · Selected: /protocolVersions/0
"2027-01-01"Rule Source Code
Section titled “Rule Source Code”document.yaml at immutable tag v0.9.0-rc.3.