Plugin skill invoked via Skill tool does not inject SKILL.md body (Linux, 2.1.177; sibling of #25834)

Summary

Invoking a plugin-provided skill directly via the Skill tool dispatches but the
skill's SKILL.md body is never injected into context. The tool result is only:

Launching skill: brooks-lint:brooks-review

followed by the generic dispatch turn:

Use the Skill tool to invoke the `brooks-lint:brooks-review` skill, then follow its instructions exactly.

No SKILL.md content, no error. The agent is told to "follow its instructions exactly"
but the instructions are absent — it reads as circular. The skill only becomes usable
if you manually Read the SKILL.md from the plugin cache.

Environment

• Claude Code 2.1.177 (Linux / WSL2)
• Plugin: brooks-lint from marketplace hyhmrright/brooks-lint, cached at

~/.claude/plugins/cache/brooks-lint-marketplace/brooks-lint/1.2.3/

• Enabled in settings.json: "brooks-lint@brooks-lint-marketplace": true

Reproduction

1. Install the marketplace plugin and enable it.
2. Invoke any plugin skill via the Skill tool, e.g. Skill(skill="brooks-lint:brooks-review").
3. Observe: only the "Launching skill / Use the Skill tool to invoke..." dispatch text

appears; the SKILL.md methodology is not injected.

Affects all six of the plugin's skills.

Verified NOT a plugin/config problem

• .claude-plugin/plugin.json is valid; skills are auto-discovered at skills/<name>/SKILL.md

with valid frontmatter (they DO appear in the session's available-skills list).

• Reading the SKILL.md files manually works perfectly — content is intact.
• So the plugin is spec-conformant; the failure is in the **Skill-tool dispatch / SKILL.md

injection path**.

Relationship to existing issues (please confirm same root cause vs. new)

• #25834 ("Plugin agent skills: frontmatter silently fails to inject skill content")

is CLOSED/completed (2026-02-17, labeled platform:macos). That issue is about a plugin
agent referencing a plugin skill via the skills: frontmatter array. This report
is the direct Skill-tool invocation path on Linux, still failing on 2.1.177 — likely a
sibling of the same injection bug, or a regression/incomplete fix.

• #15178 (OPEN) is the inverse (skills missing from <available_skills>); here the skills

ARE listed, they just don't inject on dispatch — so not the same.

Workaround

Read ~/.claude/plugins/cache/<marketplace>/<plugin>/<version>/skills/<name>/SKILL.md
directly and follow it by hand.