Use ListTagsForVault with an Amazon SDK or command line tool

    /// <summary>
    /// List tags for an Amazon S3 Glacier vault.
    /// </summary>
    /// <param name="vaultName">The name of the vault to list tags for.</param>
    /// <returns>A dictionary listing the tags attached to each object in the
    /// vault and its tags.</returns>
    public async Task<Dictionary<string, string>> ListTagsForVaultAsync(string vaultName)
    {
        var request = new ListTagsForVaultRequest
        {
            // Using a hyphen "-" for the Account Id will
            // cause the SDK to use the Account Id associated
            // with the default user.
            AccountId = "-",
            VaultName = vaultName,
        };

        var response = await _glacierService.ListTagsForVaultAsync(request);

        return response.Tags;
    }

The following command lists the tags applied to a vault named my-vault:

aws glacier list-tags-for-vault --account-id - --vault-name my-vault

Output:

{
    "Tags": {
        "date": "july2015",
        "id": "1234"
    }
}

Amazon Glacier requires an account ID argument when performing operations, but you can use a hyphen to specify the in-use account.