The phrase "a valid role" is correct and usable in written English.
It can be used when discussing the appropriateness or legitimacy of a particular function or position within a context, such as a job, organization, or system.
Example: "In our project, each team member has a valid role that contributes to our overall success."
Alternatives: "an acceptable position" or "a legitimate function".
There is, of course, a valid role for lobbyists.
Dual capitalization plans can have a valid role in acquisitions and business development, these proponents contend.
Psychologists have a valid role to play in keeping civil aviation safe.
"I will be explicit: you cannot, in my opinion, believe that secrecy jurisdictions like the Bahamas have a valid role when that role is to undermine the rule of law in other countries and also be UK home secretary".
There is a valid role for tax cuts at a time of large budget surpluses, especially if they are tailored for an important purpose -- for example, helping low-income families buy health insurance.
Coca-Cola said: "As one of the longest, continuous sponsors of the Olympic movement, we are proud that we are able to use our sponsorship to enable millions of people to experience the Games and believe we have a valid role to play.
By describing her original book as "women's lib prehistory", they evaded the force of her critique and simultaneously used the aquatic ape (by means of guilty association) to question whether feminism could play any valid role in science.
Protecting a country against threats short of war remains a valid military role, though it suggests a very different shape of force when neighbors are reliably friendly.
According to our statistical analysis, parameters characterizing ocular circulation, such as retinal and choroidal blood flow and retinal arterial or venous calibers did not play a valid explanatory role for retinal bleeding during a high altitude expedition.
The opinion cited the valid role of restrictions in protecting "the integrity of the electoral process" and in enabling "a fairer election debate".
So, in your efforts to gain more experience in the fields you want to pursue, think about ways that you can create a position for yourself that will not only help you develop the skills you need, but also provide you with valid roles that you can reference on your resume/CV.
