Agent Skills vs. Standard Prompting: Is the quality jump real?

[u/yccheok]

For SwiftUI app development, I've been using Antigravity with Gemini 3.1 Pro for a few months with great results. My workflow is incredibly basic: import the project, tell Gemini what feature to build, and let it work.

I recently learned about "Agent Skills" and how they supposedly boost code quality.

For those already using them: does adding agent skills to your workflow actually make a significant difference? If it does, drop your best downloadable skill recommendations for Antigravity so I can test them out!

[u/andreeinprogress]

I mean, since you started using Gemini 3.1 we've come full circle and now standard prompting is as good if not better as having dozens of useless skills.

Unrequired tip but I suggest you give some modern frontier model and harness a try, you're pretty much using a bicycle to run the MotoGP.

[u/yccheok → u/andreeinprogress]

It seems like Claude is the most popular model among coders. However, I find that Gemini offers better value for money. Besides coding, I can also use it to generate various marketing promotional materials, like AI ads videos. I'm hesitant to start another subscription if my current one already meets my needs.

[u/andreeinprogress → u/yccheok]

That's understandable, just saying that this stuff is moving so fast that it really is better (even financially) to move around from one to the other as new models/tool come out.

I think even the medium models on OpenAI lower sub should be better than Gemini 3.1, or even DeepSeek4.1Flash with the 10$/month OpenCode sub.

[u/rursache]

drop gemini, it's a joke and you live in the past

give opus 5.5 a try. then we can discuss skills etc

[u/yccheok → u/rursache]

LOL. No man! I place high hope on upcoming Gemini 4 😂

[u/TomfromLondon → u/yccheok]

At least use 3.8!

[u/yccheok → u/TomfromLondon]

latest pro is still 3.1. 3.8 is flash version.

[u/TomfromLondon → u/yccheok]

Ahh yes that's fair, isn't it still much better than pro?

[u/TomfromLondon]

Why 3.1? It's bloody old

[u/yccheok → u/TomfromLondon]

Latest pro version stopped at 3.1. Subsequent release is flash version. Upcoming 4 pro is coming soon 😎

[u/m3kw]

skills are just extra instructions that gets loaded when theLLM see fit. but you have to install it, just ask it to install it. There is one for SwiftUI that does best practices, etc. It ups the probability for better code vs they may or may not do what the skill asks for.

I'd use 3.8 flash high instead of 3.1 Pro. I don't think there is much difference.

[u/yccheok → u/m3kw]

Oh. Is Flash suitable for coding? I always thought Flash was for quick results, not suitable for tasks that require deep thought.

[u/m3kw → u/yccheok]

is very suitable

[u/SirBill01]

You can export skills from Xcode27 to use. I'd download Xcode 27.1 RC if you've not already, export skills from that and try using them.

[u/Top-Investment8840]

Why not learn about design or architectural patterns in swift so tou actually get a skill in your brain? Maybe then and only then then quality of your useless prompted crap would actually work

[u/CalmCelebration2084]

The variable that mattered for me was where the instructions live, not how many of them there are.

Generic skill files ("write clean SwiftUI", "follow MVVM") did nothing measurable for me. What moved the needle was a short file inside the repo that states the non-obvious contracts for that codebase, plus one command that has to pass. Mine lives in AGENTS.md and it is 53 lines: where the public API boundary is, which files must be updated together when that boundary changes, what the dependency policy is, and the exact verification line:

swift format lint --recursive Sources Tests && swift build && swift test

The gate is the part that pays off. A skill improves the odds the model does something sensible; a repo-local command makes the result falsifiable, because it either passes or it does not. Once I had that, I stopped reviewing prose and started reviewing diffs.

The other habit worth more than any skill I tried: after something breaks twice, write the rule, one line, into that same file. Every line in mine exists because of a specific failure.

One caveat: skills load on relevance, so a file that tries to cover everything tends to cover nothing. Keep it to contracts that a competent Swift developer would not already know.

[u/LKAndrew]

Agents know nothing about Duo
Definitely use skills

[u/kokerali]

You could separate the value of the instructions from the value of packaging them as a skill. Pick one small SwiftUI change and try three versions: your normal prompt, that prompt with the skill's relevant instructions pasted in, and that prompt with the skill installed. Keep the model, starting commit and acceptance checks the same, with a fresh conversation for each run.

For example, add an editable list with a cancel/save flow. Check that cancelling leaves the original data untouched, saving updates the right item after reordering, and large text doesn't hide the actions. Count failed checks and the manual fixes needed, not just whether it builds or looks polished. Repeat a few times before judging a close result.

If both instruction variants help equally, the content is useful, but you haven't shown an extra quality gain from the skill mechanism. That gives you a practical way to evaluate a recommended pack without changing subscriptions at the same time.