IFLY_INDIGO
We are talking about two things here.
Engine failure
Your company Performance Manual will (hopefully) have a correct calculated max T/O Mass for each RWY you are flying from. This gives you the max T/O Mass + procedure, so you will able to safely fly up to a safe altitude in case of an engine failure = it keeps you away from obstacles
All engine T/O
Here you as a pilot have to calculate and comply with the restriction laid out in the SID. These restrictions can be due to noise restriction, ATC or obstacles. Use the formula I wrote earlier.
You can NOT do what "rudderrudderrat" wrote earlier :
"Your NAV display with Constraints will show the ALT required in magenta to make the required gradient. If they appear in amber, then you will need to speed intervene / delay acceleration etc."
because very often these restrictions are not in your FMS as a waypoint/restriction.