---
title: "Limited validation for early MCP protocol versions"
description: "MCP 2024-11-05 and 2025-03-26 receive structural and selected checks, not a claim of complete MCP semantic conformance. The warning describes a validation limitation rather than an"
source: "https://mcpdesc.org/docs/rules/0.9.0-rc.3/mcpdesc/legacy-protocol-validation-scope/"
---

MCP 2024-11-05 and 2025-03-26 receive structural and selected checks, not a claim of complete MCP semantic conformance. The warning describes a validation limitation rather than an invalid document. Adding a later protocol version does not make checks for the earlier versions complete.

## Requirement

A document applying to MCP 2024-11-05 or 2025-03-26 is reported as receiving structural and selected checks only, not complete MCP semantic conformance.

## Details

**Rule ID:** `mcpdesc.legacy-protocol.validation-scope`  
**Owner:** mcpdesc  
**Surface:** Document · **Path:** `protocolVersions`  
**Kind:** mcpdesc-semantic  
**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     |
| ---------- | ---------- | -------------- | -------------- | -------------- |
| applies    | applies    | not-applicable | not-applicable | not-applicable |

## Required by

* **MCP Description 0.9.0, Sections 3.5 and 16.2; Proposal 0024, Section 4.1**  
  * 16\. Conformance: [req-legacy-validation-scope](https://mcpdesc.org/docs/specification/0.9.0-rc.3/conformance#req-legacy-validation-scope)
  * [proposal-snapshots/0024-validation-rule-identity-and-provenance.md](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/proposal-snapshots/0024-validation-rule-identity-and-provenance.md)
  * 1. Elicitation Declarations: [req-elicitation-legacy-incomplete](https://mcpdesc.org/docs/specification/0.9.0-rc.3/elicitation#req-elicitation-legacy-incomplete)

## Examples

### Accepted with a warning

Source: [expected-warning/legacy-result-meta.json](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/fixtures/expected-warning/legacy-result-meta.json) · Selected: `/protocolVersions`

```json
[
  "2024-11-05",
  "2025-03-26"
]
```

## Rule Source Code

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