You can create a Policy to run inventory:
https://www-secure.symantec.com/connect/articles/inventory-solution-policies-avoid-issue-tech187623
and you should then be able to run it from the agent.
If you use a Managed Software Delivery Policy to deliver the Software you can add a Task to run inventory afterwards. If you get the Policy to run the compliance chack daily make sure you create a Filter of machines with Software xx and exclude that from the Target.
I create ad-hoc Tasks to run Inventory anyway, that way you don't need to run Inventory from the client, you can do it from the console.