docs(skills): clarify external dir mutations

website/docs/user-guide/features/skills.md

@@ -236,7 +236,8 @@ Paths support `~` expansion and `${VAR}` environment variable substitution.
 
 ### How it works
 
-- **Read-only**: External dirs are only scanned for skill discovery. When the agent creates or edits a skill, it always writes to `~/.hermes/skills/`.
+- **Create locally, update in place**: New agent-created skills are written to `~/.hermes/skills/`. Existing skills are modified where they are found, including skills under `external_dirs`, when the agent uses `skill_manage` actions such as `patch`, `edit`, `write_file`, `remove_file`, or `delete`.
+- **External dirs are not a write-protection boundary**: If an external skill directory is writable by the Hermes process, agent-managed skill updates can change files in that directory. Use filesystem permissions or a separate profile/toolset setup if shared external skills must stay read-only.
 - **Local precedence**: If the same skill name exists in both the local dir and an external dir, the local version wins.
 - **Full integration**: External skills appear in the system prompt index, `skills_list`, `skill_view`, and as `/skill-name` slash commands — no different from local skills.
 - **Non-existent paths are silently skipped**: If a configured directory doesn't exist, Hermes ignores it without errors. Useful for optional shared directories that may not be present on every machine.
@@ -250,7 +251,7 @@ Paths support `~` expansion and `${VAR}` environment variable substitution.
 └── mlops/axolotl/
     └── SKILL.md
 
-~/.agents/skills/               # External (read-only, shared)
+~/.agents/skills/               # External (shared, mutable if writable)
 ├── my-custom-workflow/
 │   └── SKILL.md
 └── team-conventions/