Steps to reproduce:

1. Open https://www.zabbix.com/documentation/current/en/manual/config/items/itemtypes/zabbix_agent/zabbix_agent2#mqtt.get
2. Open https://www.zabbix.com/documentation/current/en/manual/appendix/config/zabbix_agent2_plugins/mqtt_plugin
3. Open https://www.zabbix.com/integrations/mqtt

Result:

First documentation says that topic parameter of mqtt.get item key is mandatory, the second in contradiction that Plugins.MQTT.Default.Topic zabbix_agent2.conf parameter, default topic for MQTT subscription is used if no value is specified in an item key or named session (the same as for broker URI, which is not mandatory).

The third says "The first two parameters broker and topic, broker URI can be empty, but the topic parameter is mandatory.", but it is not explicitly clear, if it is about respective zabbix_agent2.conf parameter or about an item key parameter - I believe (not tested yet), that it is meant as that it is mandatory at least in one of those places, and in such case the sentence could be extended to "The first two parameters broker and topic, broker URI can be empty, but the topic parameter is mandatory either in module configuration, or in item key configuration (at least one of them shall be configured appropriately)." or something like that.

Expected:

All 3 documentation pages explicitly clear, aligned, without contradictions.

I apologize, if this is about my imperfect attention or understanding.