---
title: "Use completion context only where supported"
description: "Completion context was added in MCP 2025-06-18. A completion example spanning an earlier supported version cannot carry that context unchanged. Split the declaration's scopes when "
source: "https://mcpdesc.org/docs/rules/0.9.0-rc.3/mcp/completion-context-protocol-version/"
---

Completion context was added in MCP 2025-06-18\. A completion example spanning an earlier supported version cannot carry that context unchanged. Split the declaration’s scopes when context is needed for only the newer versions.

## Requirement

A completion example carries context only from MCP 2025-06-18, where CompleteRequest defines it.

## Details

**Rule ID:** `mcp.completion.context.protocol-version`  
**Owner:** mcp  
**Surface:** CompleteRequest · **Path:** `context`  
**Kind:** structural  
**Requirement level:** must  
**Status:** internal · **Enforcement:** internal

## Protocol version applicability

| 2024-11-05     | 2025-03-26 | 2025-06-18 | 2025-11-25 | 2026-07-28 |
| -------------- | ---------- | ---------- | ---------- | ---------- |
| not-applicable | applies    | applies    | applies    | applies    |

## Required by

* **MCP Description 0.9.0, Sections 10.4.6 and 11.4**  
  * 10\. Resources and Resource Templates: [req-template-completion-context-protocol-version](https://mcpdesc.org/docs/specification/0.9.0-rc.3/resources#req-template-completion-context-protocol-version)
  * 1. Prompts: [req-prompt-completion-context-protocol-version](https://mcpdesc.org/docs/specification/0.9.0-rc.3/prompts#req-prompt-completion-context-protocol-version)

## Based on

* **Tier 1 — MCP schema.ts and normative specification text:** MCP 2025-03-26 schema.ts, interface CompleteRequest (no context); MCP 2025-06-18 to 2026-07-28 schema.ts, CompleteRequest params context  
  * [validation/mcp-schemas/2025-03-26/schema.ts#L1092-L1113](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/schema/2025-03-26/schema.ts#L1092-L1113)
  * [validation/mcp-schemas/2025-06-18/schema.ts#L1307-L1340](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/schema/2025-06-18/schema.ts#L1307-L1340)
  * [validation/mcp-schemas/2025-11-25/schema.ts#L1995-L2025](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/schema/2025-11-25/schema.ts#L1995-L2025)
  * [validation/mcp-schemas/2026-07-28/schema.ts#L2582-L2618](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/schema/2026-07-28/schema.ts#L2582-L2618)

## Notes

MCP Description does not support completion examples for MCP 2024-11-05 (mcp.completion.protocol-version).

## Examples

### Invalid example

Source: [expected-invalid/invalid-completion-example-semantics.json](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/fixtures/expected-invalid/invalid-completion-example-semantics.json) · Selected: `/prompts/1/completionExamples/context-too-early`

```json
{
  "argument": {
    "name": "name",
    "value": "a"
  },
  "context": {
    "arguments": {
      "department": "engineering"
    }
  },
  "result": {
    "completion": {
      "values": [
        "Ada"
      ]
    },
    "_meta": {
      "captured": true
    }
  }
}
```

## Rule Source Code

[example.yaml](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/validation/rules/example.yaml) at immutable tag [v0.9.0-rc.3](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft).