Empty metadata --> tool tag causes parsing exception

[YanWittmann]

Hello, I have a question regarding an exception I get when parsing a 1.3 CycloneDX SBOM.

According to the specification, the <tools> tag in the <metadata> section is an array, which does not specify a constraint to it's size: https://cyclonedx.org/docs/1.3/json/#metadata_tools

However, when I try to parse an SBOM like this using your library:

<?xml version="1.0" encoding="utf-8"?>
<bom xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" serialNumber="urn:uuid:da658586-9285-4d22-9340-b791f4637b69" version="1" xmlns="http://cyclonedx.org/schema/bom/1.3">
  <metadata>
    <tools /> <!-- or <tools></tools> -->
  </metadata>
</bom>

I get this exception:

com.fasterxml.jackson.databind.JsonMappingException: Cannot coerce empty String ("") to `org.cyclonedx.model.Tool` value (but could if coercion was enabled using `CoercionConfig`)
  at [Source: UNKNOWN; byte offset: #UNKNOWN] (through reference chain: org.cyclonedx.model.Bom["metadata"])

The SBOM is generated using a tool, but it does not fill out this property.
I was wondering whether this behavior is intended or whether this is a difference to the specification that I did not understand.

Thank you for your time.