A realistic scope should state what is included, what is optional, and which decisions depend on evidence or third-party services. That keeps the engagement easier to approve and manage.
The main scope drivers are research depth, positioning and brand work, product complexity, integrations, content readiness, launch requirements, and post-launch support.
A useful first proposal connects the business objective to the decisions, deliverables, dependencies, and measurement needed. Discovery clarifies that scope without pretending every engagement is identical.