Each tool maps to a distinct action-resource pair: search the mailbox, read one message by uid, create a draft, list labels. There is minor conceptual proximity between gmail_search and gmail_labels, but the descriptions make the boundary clear (label enumeration vs. message querying).

All four tools follow a uniform snake_case gmail_<verb>|noun pattern (gmail_search, gmail_read, gmail_draft, gmail_labels). No mixed conventions or vague verbs.

Four tools is lean but defensible for a narrowly scoped draft-oriented Gmail server: search, read, draft, labels cover the core loop. It edges toward thin since there is no tool to inspect or manage existing drafts.

The search → read → draft workflow is closed and send is deliberately omitted, but draft lifecycle is incomplete: no listing, updating, or deleting of existing drafts, so an agent can create duplicate drafts with no way to check. gmail_read surfaces attachment metadata but there is no way to fetch attachment content.