What criteria should the requirements meet?

Requirements should be:

• Clear and understandable — so that all project participants have the same understanding of the task.
• Complete — covering all necessary aspects of the system.
• Unambiguous — to eliminate ambiguity.
• Verifiable — so that compliance can be objectively assessed.
• Realistic — matching the capabilities of the team and technologies.
• Current — reflecting the current business needs.
• Traceable — so that the connection between requirements and implementation can be traced.

For example, a requirement "The system must process up to 1000 requests per second" is a specific, measurable, and verifiable requirement.