need another set of braces for composer.json?

the composer.json file would not work for me until I added an external set of braces around the supplied piece of code:

{"repositories": [
{
"type": "vcs",
"url": "http://github.com/engineyard/ey-php-performance-tools"
}
],
"require": {
"php": ">=5.3.3",
"engineyard/php-performance-tools": "dev-master"
}
}

Start by locating the documentation or README section that supplies the composer.json snippet. Check the snippet as a complete Composer JSON document and compare it with the reported working form. Done means the documented example parses correctly without requiring users to infer missing outer structure.

Written by the indexing model from the issue text.