How handoffs fail
The receiving agent re-asks the user for information the previous agent already collected, or redoes analysis already done. Both look like incompetence to the user and both are pure cost.
The cause is almost always the same: the handoff passed the conversation but not the state. The receiving agent has the transcript and no statement of what has been established.
Scope and hand-back
The second failure is an agent attempting work outside its remit because nothing told it where the boundary was. Stating the scope explicitly, and stating that out-of-scope requests hand back, prevents most of it.
Handoffs are also expensive: each one starts a new context with its own fixed overhead. Two agents where one would do is a doubled overhead, so keep the topology as flat as the problem allows.