A potentially fatal flaw for Scrum Teams is to step into execution before aligning on fundamental intent. A "ready, fire, aim" strategy can work if a Scrum Team is effective in the adapt phase of the inspect and adapt cycle, but for a new team that is not yet proficient in adjusting course, getting started in the wrong direction can be an impediment that the Scrum Team is not yet able to overcome.
Aligning on fundamental intent is the job of the Product Owner in Scrum. Getting this role right is key to success. The Product Owner is responsible for 4 key things:
Direction - The Product Owner establishes and nurtures a vision and sets direction by building a backlog of candidate features ordered so as to deliver the highest possible value towards the vision.
Feedback - The initial Product Backlog is built at the time when the Product Owner knows the least about what is needed to make the product a success. The iterative nature of Scrum relies on feedback on the features as they are built to inform work going forward.
Correcting - It is the nature of a Product Backlog for the content and order to evolve as a direct result of feedback. An improving Product Backlog is an indicator that agility is happening.
Deploying - Getting the product in the hands of the customer is the whole point. Customers using the product is where value is realized... and feedback provided through actual use is the most informative and useful for decisions on future product direction.
... and one more thing — communication! To keep a coalition of stakeholders and a cadre of performers aligned in a dynamic, shifting environment, the Product Owner needs to ensure everyone has an transparent, unobscured view to the current direction.