extract-ssot
Extract SSOT
Why this skill exists
Codifies the markdown-SSOT-extraction pattern as a repeatable workflow. Each invocation targets ONE cluster of repeated markdown content and resolves it to a single named source of truth — consolidating into an existing SSOT home when one already owns the concept, otherwise creating a new artifact (e.g. a rule file or a new skill) — plus migration of all call sites to cite by exact heading.
The principle is the coding Rule of Three / DRY, applied to markdown text. If the same unit of prose appears 3+ times, changes together, and has an identity that can be named, collapse to one definition and reference by name. Below 3 instances, inline is the disciplined call — premature abstraction is the dominant failure mode.
Typical markdown extraction shapes the workflow handles:
- A vocabulary of CLI/API verbs that many prompts, skills, and rules invoke inline — collapsed into one rule file with stable headings the call sites cite
- A constraint or guardrail repeated across multiple skills (e.g. "always run X before Y") — promoted to a single always-loaded rule
- A workflow primitive appearing across several skills — extracted to a shared primitive doc that skills cite by name
Extraction is dangerous: ~19% failure rate even on curated skills (SkillsBench, n=84 tasks), ~50% on practitioner-authored skills (40-skill failure analysis). This skill encodes the guardrails (Rule of Three, categorical-shape test, ≤500-line bound, one-level-deep mandate, Metz unwind procedure) so each invocation is reversible and reviewable.
Code / config escape-hatch. Repeated string literals, magic constants, helper functions in source code, or repeated CI / settings / MCP stanzas in config files are also extractable in principle (Rule of Three applies). This skill flags such clusters during identify but does NOT ship a citation contract for them — the caller uses the language-idiomatic form (import / using / source, YAML anchor, JSON $ref, build-tool include) and language-aware refactoring tools (IDE rename, Roslyn / ts-morph). Markdown is the only file class with no language-level rename safety net — that is where the contract here adds value.