Two-Descriptions-OK

for now, somehow fixed this way:

env:
  # Uses docker.io for Docker Hub if empty
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}
  IMAGE_DESCRIPTION: My Docker image on GitHub Container Registry
  VERSION: ${{ github.ref_name || 'latest' }}
  
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
           ...
          annotations: |
            org.opencontainers.image.description=${{ env.IMAGE_DESCRIPTION }}
        env:
          DOCKER_METADATA_ANNOTATIONS_LEVELS: manifest,index

      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@v6.18.0
        with:
           ...
          annotations: |
            ${{ steps.meta.outputs.annotations }}
            org.opencontainers.image.description=Per-arch image description for each variant
          ...
          outputs: type=image,name=target,annotations.index:org.opencontainers.image.description=My multi-arch image

Gives me what I at least 80% expected: