One plugin equals one craft

The rule is simple to state and hard to follow: one plugin, one craft. When you violate it, you will not notice immediately. The output will seem fine. The degradation is gradual, and it looks like model limitations rather than architectural drift.

What a craft actually is

A craft is a domain of expertise with three markers: a distinct vocabulary, a distinct quality bar, and a distinct set of failure modes. Engineering has its own vocabulary (invariants, coupling, throughput). It has its own quality bar (correctness, then performance, then readability). It has its own failure modes (concurrency bugs, off-by-one errors, premature optimization).

Poetry also has a vocabulary (meter, caesura, enjambment). It has a quality bar (the word that could not be any other word). It has failure modes (sentimentality, forced rhyme, decoration without compression).

A craft is not a job title. A "creative technologist" is a job title, not a craft. It names a person who does two things. The Constellation splits them.

The test for plugin boundaries

Three questions. If you can answer all three without hesitation, you have a craft:

One — can you describe the craft in one sentence? Not a paragraph. One sentence. "great-authors owns prose: the selection, arrangement, and revision of words to produce a specific effect in a specific reader."

Two — can you name three people who exemplify the craft at its best? Real people, historical people, fictional people. The names are not decoration. They are the quality bar made concrete. When you cannot name three people, you cannot train the model on the register.

Three — can you name what this craft does not do? Every craft has a negative space. great-authors does not make format decisions. That is great-publishers. great-filmmakers does not write dialogue. That is great-authors. The negative space is as important as the positive definition.

What happens when you mix crafts

A prompt that asks a single persona to write copy and then decide the packaging format will produce copy that unconsciously bends toward the packaging constraints it is about to encounter. The writer starts making publisher decisions without declaring them. The output is coherent, but not optimized for either craft.

This is subtle because it still looks like output. It is only when you run the same task through a clean great-authors session, then hand the artifact to a clean great-publishers session, that you see the difference. The separate passes produce better copy and a more deliberate format choice.

The one legitimate exception

Early in a project, when you are still discovering what the work requires, you may run a broad session to map the terrain. This is not a violation of the rule — it is reconnaissance. The output of that session is not the artifact. It is a brief. You then split the brief into craft-specific sessions.

Reconnaissance is allowed. Shipping the reconnaissance as the final artifact is not.

If you get stuck

If you are unsure whether two crafts belong in one plugin or two, look at the failure modes. If the failure modes are different, the crafts are different. If a plugin session could fail in two distinct ways that require different diagnostics, the plugin is holding two crafts.

If splitting the plugin seems like too much overhead, you are probably not splitting at the right seam. The split should feel like relief — like two sessions that each know exactly what they are doing, rather than one session that is unsure.

Cross-reference

Lesson 6 (Why mixed registers fail) gives a worked example of what happens when you put two crafts in one context window and let them run.

Deliverable

Pick one task you currently give Claude in a single session. Apply the three-question test. If it passes, name the craft. If it fails, name where the split should go and what the two crafts are.

Further reading

• "When You Draw Departments Inside a Plugin, You've Found a Split" — the diagnostic that says a plugin is holding two crafts: the moment you draw an org chart inside it.