When is it not fine to make mistakes? You say that intentions go a long way (towards something), which makes it sound like it all depends on how this mistake is

When is it not fine to make mistakes? You say that intentions go a long way (towards something), which makes it sound like it all depends on how this mistake is received by the transgender person. If there is no objective rule on how to acceptably address trans people, why should we enforce an imaginary rule?