[DOCS] SessionStart hook docs omit `reloadSkills: true` for same-session skill discovery

Documentation Type

Missing documentation (feature not documented)

Documentation Location

https://code.claude.com/docs/en/hooks

Section/Topic

SessionStart decision control and the SessionStart row in the JSON output summary table

Current Documentation

The hooks reference currently says:

| SessionStart, Setup, SubagentStart | Context only | hookSpecificOutput.additionalContext adds context for Claude. SessionStart also accepts [initialUserMessage and watchPaths](#sessionstart-decision-control). No blocking or decision control |

And the SessionStart decision control section currently lists only:

| additionalContext | String added to Claude's context at the start of the conversation, before the first prompt. | | initialUserMessage | String used as the first user message of the session. | | watchPaths | Array of absolute paths to watch for FileChanged events during this session |

What's Wrong or Missing?

Changelog v2.1.152 introduced a new SessionStart hook output:

SessionStart hooks can now return reloadSkills: true to re-scan skill directories, making skills installed by the hook available in the same session

But the hooks reference does not document that field anywhere outside the changelog.

That leaves a concrete gap for hook authors:

A. The supported SessionStart output is missing from the reference

The JSON output summary table and the SessionStart decision control section both read as if additionalContext, initialUserMessage, and watchPaths are the complete SessionStart-specific outputs.

B. The same-session skill-install workflow is not discoverable

The current docs tell readers that creating a top-level skills directory after session start normally requires a restart, but they do not explain that a SessionStart hook can now request a skill-directory re-scan so newly installed skills become available in that same session.

Suggested Improvement

Add reloadSkills to both hooks reference locations that enumerate SessionStart-specific outputs.

Suggested wording for SessionStart decision control:

| reloadSkills | Boolean. When true, Claude Code re-scans configured skill directories after the hook completes so skills installed by the hook are available in the current session. |

Also update the summary table row for SessionStart to mention reloadSkills alongside additionalContext, initialUserMessage, and watchPaths.

If you want the workflow to be easier to find, add a short cross-reference from the skills docs noting that SessionStart hooks can request a rescan when they install skills at startup.

Impact

Medium - Makes feature difficult to understand

Additional Context

Affected Pages:

| Page | Line(s) | Context |
|------|---------|---------|
| https://code.claude.com/docs/en/hooks | 795 | SessionStart summary row lists additionalContext, initialUserMessage, and watchPaths, but not reloadSkills |
| https://code.claude.com/docs/en/hooks | 883-889 | SessionStart decision control table omits reloadSkills |
| https://code.claude.com/docs/en/skills | 114 | Skills docs say creating a top-level skills directory after session start requires a restart, with no cross-reference to the new SessionStart rescan capability |

Total scope: 3 pages affected

Relevant release: v2.1.152