Design Tree Core
Overview
This skill is the shared governance core for the design-tree skill family.
It is not a general design skill.
It is not a user-facing entrypoint for normal design work.
It exists to define the minimum shared contract that all design-tree skills must honor.
Its job is to protect only the rules that stay stable across the family:
- required fields (including the mandatory )
- vocabulary and the prohibition on silent inference
- derivation criteria
- parent/child handoff contracts
- anti-bloat governance
When to Use
Use this skill only when:
- maintaining or revising the design-tree skill system itself
- changing the shared contract
- aligning multiple design skills on behavior
- deciding whether a new design tree should be derived
- checking whether shared design-tree rules belong in a common core
- aligning multiple design skills on shared boundary or handoff rules
- preventing design-tree drift, duplication, or bloat
Do not use this skill when:
- the user needs normal design routing
- the task is to create an initial design tree
- the task is to refine an existing design tree
- the task is to evaluate a bounded design decision
- the task is to check whether a design is ready for planning
- the task is to write a design doc, report, note, or plan
- the task is to store project-specific conclusions, examples, or temporary guidance
Core Responsibility
This skill owns only rules that are all of the following:
- Shared across at least two design-tree skills
- Stable over time
- Directly relevant to design-state boundaries, routing, derivation, handoff, or anti-bloat governance
- Too central to leave implicit
- Too shared to belong to only one skill
If a rule fails any of those tests, it does not belong here.
Forbidden Content
The following content must not be added to this skill or its references:
- project-specific conclusions
- one-off discussion outcomes
- long examples or case studies
- detailed templates
- persistence adapters or repo-specific save workflows
- release workflow details
- single-skill-specific rules
- content-production rules for reports, notes, or plans
- FAQ-style patch accumulation
- explanatory expansions that do not change shared design-tree behavior
If content is useful but not core, move it elsewhere.
Admission Rule
New content may enter this skill only if it satisfies all checks below:
- It affects more than one design-tree skill.
- It is a stable rule, not a local workaround.
- It changes or protects shared boundaries, routing, derivation, handoff, or anti-bloat behavior.
- Omitting it would cause shared drift or inconsistent decisions.
- It cannot be placed more naturally in:
- a specific design skill
- a reference file for one skill
- an eval
- an example
- a design doc
- a report
- a checklist
- a script
If any check fails, reject the addition.
Eviction Rule
Content must be moved out of this skill when any of the following becomes true:
- it is only used by one skill
- it becomes project-specific
- it is mainly explanatory rather than behavioral
- it is better represented as an example, template, checklist, or script
- it increases size without increasing shared governance value
Do not keep content here just because it was historically added.
Derivation Scope
This skill may define shared rules for when a design tree should be derived into a new tree.
It must not define the full operating logic of any derived tree.
Once a derived tree has its own stable responsibility, that logic belongs in the derived tree, not here.
Shared Output Contract
Design-tree skills share one primary output contract: they produce or update
.
They do not share a default file-writing contract.
If a specific skill or repository wants to persist a design file, that behavior belongs in that skill's local reference or adapter rules, not in the shared core.
Output Contract
When this skill is used, the output should be limited to one or more of:
- shared clarification
- clarification
- shared rule clarification
- derivation decision criteria
- handoff contract clarification
- anti-bloat governance guidance
- keep / move / derive recommendations for design-tree content
It should not produce a normal design tree as output.
Maintenance Rule
Keep this skill small and rigid.
- Prefer the shortest rule that preserves shared behavior.
- Prefer moving detail out over expanding this file.
- Prefer reference files over inline accumulation.
- Prefer deletion over historical clutter.
This skill is healthy only if it remains smaller and more stable than the skills that depend on it.
Mandatory Target Type Rule
is a mandatory field of
.
No design-tree skill may silently infer, assume, default, or derive a
value.
When it is missing, every design-tree skill must treat the state as invalid and either stop or route to the step that can set it explicitly.
See REFERENCE.md section 1.2 for the full rule.
Relationship to Other Skills
- may use this skill when deciding whether to derive a new tree.
- may use this skill when rejecting a design flow that is missing .
- may use this skill when creating a derived tree.
- may use this skill when choosing the correct target-type skeleton.
- may use this skill when a branch appears to be evolving into a separate stable decision system.
- may use this skill only to detect missing required state, tree-structure drift, or mixed responsibilities.
This skill must not take over their normal responsibilities.
Reference Files
Detailed shared rules should live in companion reference files such as:
Keep
as the strict entry contract, not the full knowledge base.