Codex session inventory truncation hides installed Socket skills

[gaelic-ghost]

Problem

A Codex desktop task in the Socket repository required maintain-project-agents, but the session-provided Available skills inventory did not list it. The agent therefore reported the skill as unavailable even though the skill was authored, packaged, cached, and enabled.

The injected inventory stopped alphabetically during the Azure plugin entries. Socket currently validates 300 shared skills, so the observed behavior is consistent with the generated skill catalog being truncated before later plugins such as documentation-skills are included. The exact truncation layer still needs confirmation.

Evidence

• Authored source exists at plugins/documentation-skills/skills/maintain-project-agents/SKILL.md.
• Installed cache exists at ~/.codex/plugins/cache/socket/documentation-skills/9.35.0/skills/maintain-project-agents/.
• [plugins."documentation-skills@socket"] enabled = true is present in Codex config.
• The cached skill contains its SKILL.md, script, tests, references, template, and agents/openai.yaml.
• The session inventory included the Documentation Skills plugin root but omitted its individual skills.

Impact

Required repository workflows can be incorrectly declared unavailable. Agents then bypass the intended skill procedure even though the plugin is installed and enabled. Large marketplaces are especially vulnerable because later skill names may never reach the session context.

Desired outcome

1. Determine whether Codex truncates the available-skill catalog by prompt size, entry count, or another limit.
2. Add a deterministic Socket diagnostic that compares enabled cached plugin skills with the skills exposed to a session, if a supported session inventory surface exists.
3. Document a safe fallback for explicitly required repo skills: verify the enabled cached or authored skill, read its complete SKILL.md, and report the catalog omission instead of declaring the skill itself unavailable.
4. Report the underlying Codex inventory defect upstream with a minimal reproduction if Socket cannot fix the exposure layer directly.

Reproduction

1. Enable documentation-skills@socket.
2. Start a Codex desktop task in the Socket checkout with the full Socket plugin inventory active.
3. Inspect the injected Available skills section.
4. Observe that the list ends before documentation-skills:maintain-project-agents.
5. Verify that the skill remains present in the enabled plugin cache.