better description for predicate signatures
better description for predicate signatures

Co-authored-by: Felicity Chapman <38225497eb75acc27e4ed99ef677beddf8a5d7a2@github.com>
github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql