The frontmatter fields above are required. The section anatomy is a recommended pattern: equivalent headings such as `How It Works`, `Workflow`, or `Core Process` are fine when they preserve the same intent and keep the skill easy to follow.
The session-start hook (`hooks/session-start.sh`) injects the `using-agent-skills` meta-skill into every new Claude Code session. A regression test at `hooks/session-start-test.sh` validates the hook's JSON payload — both when `jq` is available and when it isn't.
Run it before opening any PR that touches:
-`hooks/session-start.sh`
-`skills/using-agent-skills/SKILL.md` (the meta-skill content embedded by the hook)
```bash
bash hooks/session-start-test.sh
```
Expected output: `session-start JSON payload OK`. The script exits non-zero on any assertion failure.
### Reproducing the no-jq fallback
The hook gracefully degrades to an `INFO`-priority payload when `jq` isn't on `PATH`. To exercise that branch locally, strip `jq`'s directory from `PATH` for the test invocation:
```bash
JQ_DIR=$(dirname "$(command -v jq)")
PATH=$(echo"$PATH"| tr ':''\n'| grep -v "^${JQ_DIR}$"| tr '\n'':'| sed 's/:$//')\
bash hooks/session-start-test.sh
```
This works cleanly when `jq` lives in its own directory (e.g. `/opt/homebrew/bin` from Homebrew, `/usr/local/bin` from a manual install). If your `jq` shares a system bin with other tools the test depends on (such as `mktemp` in `/usr/bin`), the simpler approach is to install `jq` via a separate package manager so it has its own bin directory, then re-run.
The hook's `command -v jq` check fails under the stripped `PATH`, the `INFO`-priority fallback runs, and the test asserts the `jq is required` guidance message instead of the normal payload.
