Compare agent skills before installing.

Catalog of this repo's measurement instruments, each with command, current baseline, and interpretation guide. Covers skill size and description budgets, orphan-ref and golden-principles scans, drift gates as signals, coverage pins, and the eval harness. Use when you say `measure this`, `read the drift signal`, `check skill budgets`. Do NOT use to fix what you measure (use `ai-agents-debugging-playbook`) or for evidence standards (use `ai-agents-validation-and-qa`).

Use this skill when releasing OpenSpec: audit merged work and changeset coverage, decide whether a catch-up changeset PR is needed, prepare or resume the Changesets Version Packages PR, cut a beta or stable release, verify publishing, and polish GitHub release notes. Also use when asked whether an open release PR is complete, what the next release step is, or to continue a release paused for human approval.