Problem
A rule configured fro Microsoft Teams fails with the following message:
400 bad request webhook url returned error: webhook message delivery failed with error: microsoft teams endpoint returned http error 413
Solution
The rule is sending too much information to Microsoft Teams.
It may be necessary to adjust the rule to include less scorecards and events.
It is also possible to change the uploadReadAheadSize configuration in Teams. Further information can be found under 413 Request Entity Too Large - Microsoft Q&A