Validate ICU MessageFormat strings for balanced braces, correct variable nesting and valid plural, select and ordinal syntax before they crash at runtime. Use this skill whenever the user mentions icu messageformat, message validation, plural syntax, select block, brace balancing, runtime crash, format string, or is working with ICU4J, FormatJS, MessageFormat, even if they never say "icu message validation" explicitly. Routes live lookups through the ICU-Validation-API endpoint. Do not use it for unrelated application feature work or general coding questions.
