A completion example must target a Prompt argument or Resource Template variable that exists. Context entries must name other declared targets, not repeat the argument being completed. Correct the example names or the declaration they describe.
Requirement
Section titled “Requirement”A completion example completes a declared Prompt argument or URI template variable, and its context names other declared arguments or variables only.
Details
Section titled “Details”Rule ID: mcpdesc.completion-example.target
Owner: mcpdesc
Surface: Completion example · Path: argument, context
Kind: mcpdesc-semantic
Requirement level: must
Protocol versions: independent of the MCP protocol version
Status: internal · Enforcement: internal
Required by
Section titled “Required by”- MCP Description 0.9.0, Sections 10.4.6 and 11.4
- 10. Resources and Resource Templates: req-template-completion-target
-
- Prompts: req-prompt-completion-target
Based on
Section titled “Based on”- Tier 1 — MCP schema.ts and normative specification text: MCP 2025-06-18 to 2026-07-28 schema.ts, CompleteRequest context.arguments (previously-resolved variables in a URI template or prompt)
Examples
Section titled “Examples”Valid example
Section titled “Valid example”Source: expected-valid/named-completion-examples.json · Selected: /prompts/0/completionExamples
{ "engineering-a": { "argument": { "name": "name", "value": "a" }, "context": { "arguments": { "department": "engineering" } }, "result": { "completion": { "values": [ "Ada", "Alan" ], "total": 2, "hasMore": false } } }}Invalid example
Section titled “Invalid example”Source: expected-invalid/invalid-completion-example-semantics.json · Selected: /prompts/2/completionExamples/bad-membership/argument
{ "name": "nickname", "value": "a"}Rule Source Code
Section titled “Rule Source Code”example.yaml at immutable tag v0.9.0-rc.3.