Being asked if you’re a team player is a standard interview question, and you’re supposed to say “yes.” But if I were asked, my answer would be: “It depends.”
If the team has an appropriate purpose and a qualified leader, and team members have well-defined roles, then yes, I’m a very effective team player.
The “team” doesn’t have a purpose, or
That purpose would be better fulfilled by an individual or a couple of people, or
It has an ineffective leader or none at all, or
(My least favorite) The “team” members don’t have clear roles; they’re just a group of people who are supposed to accomplish something as a committee.
Then, no, I probably won’t be particularly helpful if you put me on that “team.”
Teams and committees are different. A team is built. Individuals are selected because they have the skills and experience to play a particular role. In baseball, your team needs a first baseman. Playing first base requires different skills and experience than playing shortstop. In business, your team may need a network architect, who requires different skills and experience than a marketer.
The person who puts the team together—who may be the eventual leader or someone who isn’t even going to be on the team at all—has to determine which roles the team needs in order to be successful, find people with the right skills and experience to perform the roles, add them to the team, and clearly define what each member's roles will be.
On the other hand, a committee is a group of individuals who represent a larger body, such as an association’s membership committee. This committee will make decisions and move an agenda forward by consensus. On a team, the leader may unilaterally decide on a course of action based on the work performed by each team member executing their assignment. A team may form a consensus, but usually not.
But the real issue is this: We talk about teams and teamwork like they’re universally good, without giving much thought to what a team really is, or whether a team is appropriate for a given mission. That leads to assembling a “team” to complete a project, when it might be more effective to delegate the project to one or two people with the skills and experience to complete it alone—or to a committee instead of a team.
A team will likely fail if its members don’t have the right complement of skills and experience and their decision-making model doesn’t fit the requirements of the mission. So, don't call it a "team" or me a "team player."