ndf: Codex plugin hooks parse error and oversized skill descriptions

[takemi-ohama]

Summary

When loading the ndf plugin in Codex, two warnings were observed:

1. hooks/hooks.json fails to parse because the file has a top-level description field.
2. Skill descriptions are shortened because the loaded skill descriptions exceed Codex's 2% skills context budget.

Observed warnings

failed to parse plugin hooks config /home/ubuntu/.codex/plugins/cache/ai-plugins/ndf/4.16.1/hooks/hooks.json: unknown field `description`, expected `hooks` at line 2 column 15

Skill descriptions were shortened to fit the 2% skills context budget. Codex can still see every skill, but some descriptions are shorter. Disable unused skills or plugins to leave more room for the rest.

Local investigation

hooks.json

Current ndf/4.16.1/hooks/hooks.json had this structure:

{
 "description": "NDF Plugin hooks: transcript retention guard, default statusline, and Slack notifications",
 "hooks": { ... }
}

Codex appears to expect the top-level object to contain hooks only. Removing the top-level description fixed the parse warning locally. Nested hook entry description fields were left intact.

skill description budget

Local loaded skill description volume was dominated by NDF:

ndf count=48 description_chars=12333
github count=4 description_chars=1130
system count=5 description_chars=1942

After shortening NDF skill frontmatter description: values to concise trigger summaries, local NDF description volume dropped to about:

ndf count=48 description_chars=2608

After that, codex --version no longer emitted the skill-description warning in the tested environment.

Suggested fixes

1. Remove the top-level description field from plugins/ndf/hooks/hooks.json.
2. Shorten description: in plugins/ndf/skills/*/SKILL.md frontmatter so each entry is a compact one-line purpose/trigger summary.
3. Keep the detailed usage instructions in each skill body instead of frontmatter.

Notes

This issue is about the plugin source itself. I applied local cache/workspace mitigations, but they will be overwritten by future plugin updates unless fixed upstream.