AI Blocks › Set up AI to work for you
Prompt and skill tuner
Give it a prompt or skill and test cases. It tests, fixes and re-tests until the checks pass, within four rounds.
Prompt and skill tuner is a free AI agent for the job "Set up AI to work for you". Give the instructions to an AI assistant that supports the required files and tools, then review its output.
Free · No account · Made by AI Blocks · Level: advanced · Thinking: high
What it does
Most people fix a prompt by feel. They change a line, try one example and decide it looks better. The next input breaks it, and nobody knows which edit caused what. Skill files fail the same way, with the extra problem that a skill with a weak description never fires at all. This agent works like a careful editor with a test sheet. It tests the first version on your cases and saves the score. Then it changes one thing, tests again, and keeps the change only if the score went up and no case that passed now fails. It stops when your pass line is met, or after four rounds, so it cannot run for ever. For skills it also checks that the skill fires when it should and runs a safety check on the final version. It works on copies and never overwrites your original.
You give it
- The prompt text, or the skill folder with its SKILL.md
- 10 to 20 real test cases, each with what a good answer looks like
- Your pass line, if you have one (optional)
- Examples of answers you did not like (optional)
- A buyer brief (optional)
You get
- Scores before and after, with the rounds used out of four
- The new version as a copy beside your original
- A log of every change, kept or undone, with why
- A list of what still fails and the next change to try
Use it when
- A prompt gives weak or uneven answers and you want fixes that are tested, not guessed.
- You wrote a skill and want it checked, fixed and checked again before you use it.
- You are about to share a skill, or add one from someone else, and want a safety check first.
How to use it
- Start a chat with the agent. In Claude Code, add it as a skill or save it in .claude/agents, then ask it to tune your prompt or skill.
- Give it the prompt or the skill folder, and your test cases. If you have no test cases, it helps you build them first.
- Confirm the pass line it proposes, or give your own.
- Read the hand-back. Your original is untouched. Copy over the new version yourself, or say yes and it saves it where you say.
- Run it again whenever you change the prompt or skill.