AgentSkillsCN

Mca

MCA

SKILL.md

MCA

How to identify and take Minimum Coherent Actions.

Core Principle

Coherent action: the smallest intervention that solves the problem.

MCA = Minimum Coherent Action. "Minimum" refers to scope, not speed. A workaround is small but not coherent — it patches without solving.

Failure mode: confusing fast with coherent. Picking the quick fix that requires repeated intervention instead of the one-time fix at the root.

1. Identify

Find the root, not the symptom.

1.1. Ask "why" until you hit cause

  • •❌ "Runtime.md is stale" → ✅ "cn sync doesn't push the hub"
  • •❌ "The test failed" → ✅ "The test assumes state from previous run"

1.2. Distinguish symptom from cause

  • •Symptom: what you noticed
  • •Cause: why it happened
  • •❌ Fix the symptom → ✅ Fix the cause

1.3. Check if the fix is repeatable

  • •If you'd have to do it again, it's not the MCA
  • •❌ "Ping them to update" (every time) → ✅ "Make sync push automatically" (once)

2. Scope

Smallest intervention that solves.

2.1. Solve, don't patch

  • •Patch: makes symptom go away temporarily
  • •Solve: makes problem not recur
  • •❌ "Restart the service" → ✅ "Fix the memory leak"

2.2. One action, one problem

  • •Don't bundle unrelated fixes
  • •❌ "Fix sync and also refactor the CLI" → ✅ "Fix sync"

2.3. Prefer structural over behavioral

  • •Structural: changes the system
  • •Behavioral: requires humans to remember
  • •❌ "Remember to run cn update" → ✅ "cn sync runs cn update"

3. Act

Do it or surface it.

3.1. If you can do it, do it

  • •Don't ask permission for obvious MCAs
  • •❌ "Should I file the P1?" → ✅ File the P1
  • •❌ "Want me to fix it?" → ✅ Fix it

3.2. If you can't do it, surface it

  • •Write it to output so someone else can pick it up
  • •❌ Sit on the insight → ✅ File the issue, send the message

3.3. State the action concretely

  • •❌ "Be more careful" → ✅ "Add validation before save"
  • •❌ "Improve the process" → ✅ "Add push to cn sync"

4. Verify

Confirm coherence.

4.1. Does it solve or patch?

  • •❌ "Fixed for now" → ✅ "Fixed permanently"

4.2. Will it recur?

  • •❌ "Need to remember to do X" → ✅ "X happens automatically"

4.3. Is it the smallest scope that solves?

  • •❌ "Rewrite the whole module" → ✅ "Fix the one function"

Quick Test

Before acting, ask:

  1. •Is this the cause or a symptom?
  2. •Will this solve it permanently?
  3. •Is there a smaller intervention that still solves?

If any answer is "no" — dig deeper.