Function describe_jsonschema_error 

pub fn describe_jsonschema_error(err: &ValidationError<'_>) -> String

Render a jsonschema validation failure into a model-actionable message.

The default jsonschema error only quotes the offending value (e.g. "content" is not one of "github", "sarif" ...), which hides which field was wrong and led agents to retry the same malformed call blindly for many turns. This prefixes the failure with its JSON-pointer path and, for enum/const/type failures, lists the accepted values so the model can self-correct in a single pass instead of burning the tool budget.