myco-implement-update-tool-fetch-merge-put

Use this skill whenever you are implementing or fixing an update_* tool in unifi-mcp. It covers the mandatory fetch-merge-put pattern, deep_merge semantics, V2 API response gotchas, the confirm double-fetch design, LLM UX requirements for dict params, and when flat params are appropriate instead. Applies even if the user only says "add an update tool for X" without specifying the implementation approach — the pattern is required for all update tools in this project.