This is what spec driven development tries to solve.

Multiple rounds of generating small contacts documents that grow from the original idea , trying to keep each slice small enough to process for a human to approve/disprove .

Eventually it leads to a long list of tasks grouped by functionality. You start a new context and the orchestrator agent dispatches tasks to sub agents with a limited amount of information provided to each sub agent.

Also should have adversarial review and approval gates with other agents and roles.