Release 0.9.9 · uHappyLogic/cairn

Frontmatter description diet (milestone 16)

Cut all 24 plugin frontmatter descriptions (21 skills/*/SKILL.md, 3 agents/*.md) to a single independent clause of 25 words or fewer naming only what that skill or agent does — the always-on description budget drops from 1,411 words to 452 (−68%), and the longest single description from 149 words to 23.
Restructured the six heaviest descriptions from scratch and shortened the nine mid-weight ones, deleting their trigger-phrase lists, mechanics, commit subjects, sequencing, cross-skill references, "Use when…" framing, and design provenance outright — a description is a routing label, never a record, so nothing cut was relocated.
Compressed the three agent descriptions into that same shape while keeping each invocation contract as a short clause naming what the prompt carries (the task's heading text, the question's Short Title).
Enforced two machine-checkable bars across the set: no semicolon or colon in any description, and every raw frontmatter loads under yaml.safe_load with its description: line left unquoted — so the transpiler's re-quoting fallback survives as an unexercised net.
Extended CLAUDE.md's Skill Frontmatter invariant into the single home of every rule governing the frontmatter description key.
Regenerated the checked-in Antigravity tree at .agents/plugins/cairn/, with each of the 24 generated files byte-identical to its source.

De-duplicated the whole 32-file runtime layer (skills/*/SKILL.md, agents/*.md, shared/*.md) across eleven per-file sweeps, removing 7,597 words (32,758 → 25,161, −23.2%) under the rule that a sentence may be cut only where its content survives earlier in the same file, in a referenced shared procedure, or in a CLAUDE.md invariant.
Retired the ## Rules heading across the layer (−3,221 words), relocating each surviving rule into the step it constrains or into the file's opening description paragraph.
Moved editor-facing rationale out of the runtime files into the CLAUDE.md invariants (−2,772 words) and trimmed cross-file narration of counterparts to the one sentence each contract needs (−1,303 words).
Consolidated the CLAUDE.md invariants section in a single post-sweep pass, merging ten overlapping bullets (35 bullets → 25).
Ran seven fresh-context whole-layer re-audits with fix tasks between them; the runtime layer returned zero lost constraints for the last five passes and zero residual restatements for the last three.
Extended scripts/migrate_skills_to_agy.py to copy shared/ into the generated Antigravity tree, so every ${CLAUDE_PLUGIN_ROOT}/shared/<name>.md reference resolves to a file that is present.

Full Changelog: 0.9.8...0.9.9