Check my CR math, please!

[PhoenixPhyre]

Hello all--

I am working on my first from-scratch monster and would appreciate feedback on the estimated difficulty. I'm aiming for a high CR 1 following the DMG math but don't have the system-mastery intuition to know if what I came up with really will work. The monster does have some other traits (social skills mainly) that shouldn't affect the difficulty, so I've left them out. My notes are in italics.

Big Thumb (CR 1)
Small humanoid (gnome), lawful evil
Armor Class: 13 (leather armor)
Hit Points: 45 This is low per the DMG, but he'll be with a bunch of other mobs.
Stats: 11 (+0)/ 15 (+2) / 8 (-1) / 12 (+1) / 10 (0) / 8 (-1) Standard order, STR/DEX/CON/INT/WIS/CHA

Traits: Advantage on mental saves vs spells As per gnome traits.
Knows minor illusion as cantrip. Shouldn't affect CR...I think.
Poisoned Blades: DC 12 CON or 1d6 poison damage. Save for half.

Attacks:
Multiattack: Makes two shortsword attacks or throws 2 daggers.

Shortsword: melee weapon attack: +4 to hit, reach 5 ft., one target. Hit: 1d6 + 2 piercing damage

Throwing Dagger (4 max): Ranged weapon attack: +3 to hit, range 20/60 ft., one target. Hit 1d4 + 3 piercing damage.

Thoughts? Concerns? I have no idea what the party that faces him will look like--it's an episodic group with several DMs running in a shared world. Assume standard composition, average level 2.

Any help would be appreciated.

[Spore]

I don't know anything about 5e past character creation but I know that a good illusion might bring the group in a difficult spot if they all charge in the alleyway where the unconscious and heavily bleeding kid is lying.

[Ninja_Prawn]

Looks like CR 1 to me.

The attack and damage bonuses on the dagger are wrong (they should be the same as the shortsword).

Does the poison damage get applied to every attack, or is it once per turn? By my maths, the answer doesn't affect the overall CR, but ambiguity is bad practice, especially if another DM is going to be using it.

[PhoenixPhyre]

Looks like CR 1 to me.

The attack and damage bonuses on the dagger are wrong (they should be the same as the shortsword).

Does the poison damage get applied to every attack, or is it once per turn? By my maths, the answer doesn't affect the overall CR, but ambiguity is bad practice, especially if another DM is going to be using it.

Thanks. The poison should be on each attack (was 2d6, but that was too much). I oopsed the damage bonus on the daggers (had +3 dex, cut it down and didn't fix it). The attack bonus was semi-intentional--this is more of a in-your-face type of dude. Shouldn't matter much either way.

The way the game is structured is an Adventurer's Guild style (ie quest board) with each quest belonging to a certain DM. I doubt anyone else will use this particular enemy, but it's good to be consistent.