[BUG] [v0.0.7] cortex-mcp-types embedded resource annotations are silently dropped on round-trip

[marvinayisi]

Project

cortex

Description

A valid embedded MCP resource with top-level annotations deserializes into Content, but the annotations disappear when the value is serialized again.

Error Message

EMBEDDED_RESOURCE_ANNOTATIONS_ROUNDTRIP={
  "type": "resource",
  "resource": {
    "uri": "file:///tmp/demo.txt",
    "text": "hello"
  }
}

Debug Logs

N/A

System Information

Cortex crate: cortex-mcp-types 0.0.7
Commit: 7954d02
Date: 2026-04-10
OS: macOS

Screenshots

https://github.com/marvinayisi/issue-images/blob/main/mcp-embedded-resource-annotations-20260410-074112.png

Steps to Reproduce

1. Create a tiny Rust crate depending on cortex-mcp-types from this workspace.
2. Deserialize an embedded resource content block that includes valid top-level annotations.
3. Serialize the Content back to JSON and inspect the output.

Expected Behavior

The embedded resource annotations should survive the round-trip.

Actual Behavior

The round-tripped content loses the top-level annotations entirely.

Additional Context

• Authoritative spec: https://raw.githubusercontent.com/modelcontextprotocol/modelcontextprotocol/refs/heads/main/schema/2024-11-05/schema.ts
• Code path: /Users/odeili/Projects/platform/cortex/src/cortex-mcp-types/src/content.rs
• Duplicate check on 2026-04-10:
• cortex-mcp-types EmbeddedResource annotations dropped round-trip