The defeat was Bayern's second of the season in the league and the first time after 65 games that the Bavarians failed to score in a home Bundesliga game.
"We can do a lot of things better," Tuchel told a press conference ahead of Wednesday's postponed league match against Union Berlin.
"We have a lot of room for improvement. The explanation in terms of passion, bite, tackling and enthusiasm remains the same. For 70 minutes (against Werder) that was below the level we expect of ourselves."
Bayern, who are in second place on 41 points, seven off leaders Bayer Leverkusen, have a game in hand and can cut the gap with a win over Union.
"Passion, bite, enthusiasm these are the basic values," Tuchel said. "These values have to be clearly visible by us.
"This is not an easy switch to make. We are very aware of how much room we have for improvement. It is our task and my responsibility."
Bayern, who are chasing a record-extending 12th consecutive league title, still have the league's best attack with 52 goals scored and top striker Harry Kane having already netted 22 times in his first Bundesliga campaign so far.
They also face Italy's Lazio in the Champions League last 16 next month.
"We remain below our expectations in the games. We will keep demanding it until it works and we are able to show that passion that hunger and greed that is the basis," Tuchel said.
"That you feel there is a team that goes together towards their goal against any resistance."
