No cutesy tone

Specific failure description

Reassurance about data/state

Specific next action

Plain language over jargon

No blame language

Avoids forbidden words

Validation messages say how to fix

Empty state not treated as error

Backup path for persistent failures

Prefers 'we' over 'you' for blame

Generic login error

Locked account concealment

Safe password reset copy

Expired/used reset link

Registration: no account enumeration

Field validation: how to fix

No blame in validation

Session expiry reassurance

Placement guidance present

Security notes section

Specific CTAs

File path in config errors

Expected vs. received for syntax error

Missing field named explicitly

Next command or fix suggested

No raw exception names

No POSIX codes as primary message

Network ambiguity acknowledged

Permission error gives alternative

Typo/unknown subcommand helpful

Plain language first line

Diagnostic notes included