GTM API / Endorse skill by id

Endorse ONE explicit skill on a 1st-degree connection as this account (wire endorse-skill, ?action=endorse). Unlike endorse_linkedin_account_skill there is no discovery read and no auto-pick: you supply skill_id, exactly one dispatch. Skill ids exist only on skills that already carry at least one endorsement (a zero-endorsement skill is not addressable), so take them from the enrichment person-skills read. Requires a 1st-degree connection (409 not_connected). Spends the endorse_skills bucket (30/day, paced; the undo waits only 2 s, so an endorse and its undo fit back to back). Returns the echoed skill urn, endorsed_by_viewer (true after endorse) and the global endorsement_count, plus the activity-log row. Re-endorsing is a LinkedIn-side no-op; undo with unendorse_linkedin_account_skill. Contract: - MCP tool endorse_linkedin_account_skill_by_id, registry package mcp.linkedin/linkedin_accounts, mount linkedin.content. - Operation action, response envelope action. - Flags: dangerous: the MCP layer gates it behind a preview/commit token, and the effect cannot be undone through this API; paced: a call spends the endorse_skills smart-limit bucket of the account it runs on, and calls of one bucket are spaced per account. A short wait is slept by the server; a longer one answers 429 rate_limited with context.retry_after, and the same call succeeds from that moment. Parallel calls on one account queue behind each other.