```
show functions | keep description, *on | mv_expand description
```

```
{
    "error": {
        "root_cause": [
            {
                "type": "unresolved_exception",
                "reason": "Invalid call to dataType on an unresolved object ?description"
            }
        ],
        "type": "unresolved_exception",
        "reason": "Invalid call to dataType on an unresolved object ?description"
    },
    "status": 500
}
```

```
org.elasticsearch.xpack.ql.capabilities.UnresolvedException: Invalid call to dataType on an unresolved object ?description
        at org.elasticsearch.xpack.ql.expression.UnresolvedAttribute.dataType(UnresolvedAttribute.java:90)
        at org.elasticsearch.xpack.esql.analysis.Analyzer$ResolveRefs.resolveMvExpand(Analyzer.java:350)
        at org.elasticsearch.xpack.esql.analysis.Analyzer$ResolveRefs.doRule(Analyzer.java:334)
        at org.elasticsearch.xpack.ql.analyzer.AnalyzerRules$BaseAnalyzerRule.rule(AnalyzerRules.java:120)
        at org.elasticsearch.xpack.ql.analyzer.AnalyzerRules$AnalyzerRule.lambda$apply$0(AnalyzerRules.java:85)
```

It should throw a VerificationException and propagate the unresolved attribute message instead
x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/analysis/AnalyzerTests.java
containsString("Unsupported type [INTEGER] for enrich matching field [languages]; only KEYWORD allowed")
        );
    }
    public void testValidEnrich() {
        assertProjection("""
            from test
            | eval x = to_string(languages)
            | enrich languages on x
            | keep first_name, language_name
            """, "first_name", "language_name");
        assertProjection("""
            from test
            | eval x = to_string(languages)
            | enrich languages on x with language_name
            | keep first_name, language_name
            """, "first_name", "language_name");
        assertProjection("""
            from test
            | eval x = to_string(languages)
            | enrich languages on x with y = language_name
            | keep first_name, y
            """, "first_name", "y");
    }
    public void testEnrichExcludesPolicyKey() {
        var e = expectThrows(VerificationException.class, () -> analyze("""
            from test
            | eval x = to_string(languages)
            | enrich languages on x
            | keep first_name, language_name, id
            """));