◇ Could this help me?
Yes. The five events named are the right minimum trace for an agent, and the argument that you cannot debug or safely operate what you cannot see is correct. Treat the four product recommendations as a starting shortlist rather than a verdict, since structured logging of those same five events gets most of the benefit with no new vendor and no data leaving the system. This is a general practice.
Design an observability layer for the agent in this project that records, on every run: each tool call with its arguments and result, each model call with prompt, response, token counts, and cost, each decision branch with the reason the agent acted rather than escalated, the final outcome, and the total cost per task. Start with a plain structured-log implementation that adds no new dependency. Then tell me separately what a dedicated tracing product would add and what data it would receive, so that decision can be made on its own.