Can I code this?

[Morenu]

OK, I know I have seen effects done that can call a named effect if a condition is met.

I am trying to see if this can be coded (Shadow Bloodline Arcana):
"Whenever you cast a spell with the [darkness] descriptor or the shadow subschool, you gain a circumstance bonus on Stealth checks equal to the spell’s level for 1d4 rounds."

Now currently I just have an extra Action button on any Shadow or Darkness spell that qualifies and I click when I cast an appropriate spell:

[SELF] BL Arcana;SKILL: [enter spell level] circumstance 1d4rnds

and its easy and clean, but I am trying to learn.

so I want a permanent effect that checks if a spell has darkness OR shadow (not both) and if it does then apply to the PC a SKILL: (Spell level) circumstance for 1d4 rounds.

I have used the following to add CL:1 to any evocation spell so that's the direction I was thinking:

Var Tat;IF: spell;IFTAG: evocation;CL:1

Now I have a ton of extensions and a list of them in my signature. if it adds code options and is PF1e/core then I probably use it.

so the questions-
1- Can I Check for Darkness descriptor?
2- Can I apply a SKILL bonus with a duration to the caster?
3- Can I code SKILL: [spell level]?
4- and If anyone is willing to show code for any or all of this so I can figure out for future ideas?

[bmos]

IF: spell doesn't do anything AFAIK
You might be looking for
Var Tat; IFTAG: spell, evocation; CL:1

Regarding your original question,
Yes, Yes, No

[dogfisc]

Should it be
Var Tat; IFTAG: spell; IFTAG: evocation; CL: 1
because
IFTAG: spell, evocation
would match any spell and any evocation?

[bmos]

Should it be
Var Tat; IFTAG: spell; IFTAG: evocation; CL: 1
because
IFTAG: spell, evocation
would match any spell and any evocation?Good point!