Are Descartes’ tests as certain as he thinks they are?

Are Descartes’ tests as certain as he thinks they are? Are the abilities to use language and solve complex problems sufficient to distinguish between a human mind and an animal or machine mind? If these two tests are not sufficient on their own, what additional tests are necessary? Do such tests exist? Support your argument with ample citations and direct quotes from philosophers and other academic sources. If a robot like Bender in Futurama or an android like Data in Star Trek: The Next Generation existed, would their artificial intelligence meet the requirements of a mind?