Declare elicitations with their mode fields

An elicitation declaration has a name, a mode, and a message. Form mode requires requestedSchema and forbids url; URL mode requires url and forbids requestedSchema. Unknown properties are rejected.

Requirement

An Elicitation Declaration has its required fields, the fields of its mode only, and no unknown properties.

Details

Rule ID: mcpdesc.elicitation.members
Owner: mcpdesc
Surface: Elicitation Declaration
Kind: structural
Requirement level: must
Protocol versions: independent of the MCP protocol version
Document schema locations: #/$defs/elicitationDeclaration
Status: internal · Enforcement: internal

Required by

• MCP Description 0.9.0, Section 12.2
  • 12. Elicitation Declarations: req-elicitation-declaration-fields
  • 12. Elicitation Declarations: req-elicitation-name-format
  • 12. Elicitation Declarations: req-elicitation-message
  • 12. Elicitation Declarations: req-elicitation-documentation-fields
  • 12. Elicitation Declarations: req-elicitation-form-schema-required
  • 12. Elicitation Declarations: req-elicitation-form-no-url
  • 12. Elicitation Declarations: req-elicitation-url-no-schema
  • 12. Elicitation Declarations: req-elicitation-url-syntax

Examples

Invalid example

Source: expected-invalid/elicitation-branch-mixing.json · Selected: /resources/0/elicitations/0

{
  "name": "mixed",
  "mode": "form",
  "message": "Supply account details.",
  "url": "not a valid URI",
  "requestedSchema": {
    "type": "object",
    "properties": {}
  }
}

Invalid example

Source: expected-invalid/discriminated-union-members.json · Selected: /tools/0/elicitations/0

{
  "name": "approve",
  "mode": "form",
  "message": "Approve?"
}

Rule Source Code

elicitation.yaml at immutable tag v0.9.0-rc.3.