I put R&F but I assume this is also in vanilla. It's not a game breaking bug, it's pretty damn harmless, but still thought it's maybe worth reporting. It could be fixed by just explaining the tile's true nature in the ability description.
If you use the Marcus Licinius Crassus ability of "your nearest city annexes this tile into its territory" on a full sized (37 tiles) city, it just becomes the same as any other oversized tile; you can harvest it, you can claim the resource on it, but working/improving it has no benefit to your empire.
However, the real issue is, to my massive disappoint because I gunned for this Great Merchant, Great Zimbabwe doesn't count any extra bonus resources you get I was already on a city with 11 bonus resources! But I had the chance to make it 13. I guess it really is unlucky haha
TL;DR: Annex tile on a full sized city only gives you the contents of the tile, it can't be worked or have anything built on it, plus bonus resources aren't counted by Great Zimbabwe.
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As a side note, it is kinda worth keeping around as a pseudo-great engineer production booster; have Magnus in the city you're building, and have stone 1 tile out of reach. Annex it, Harvest Resource! Late game that's 300+ production, twice. Still, I'd rather have him working as intended! I think it might be potentially be a real pain to fix though, as going through the modifiers, even if you change the modifiers for city size and allowed working size, it doesn't work in game, so it's potentially a real under the hood effort.
If you use the Marcus Licinius Crassus ability of "your nearest city annexes this tile into its territory" on a full sized (37 tiles) city, it just becomes the same as any other oversized tile; you can harvest it, you can claim the resource on it, but working/improving it has no benefit to your empire.
However, the real issue is, to my massive disappoint because I gunned for this Great Merchant, Great Zimbabwe doesn't count any extra bonus resources you get I was already on a city with 11 bonus resources! But I had the chance to make it 13. I guess it really is unlucky haha
TL;DR: Annex tile on a full sized city only gives you the contents of the tile, it can't be worked or have anything built on it, plus bonus resources aren't counted by Great Zimbabwe.
--------------
As a side note, it is kinda worth keeping around as a pseudo-great engineer production booster; have Magnus in the city you're building, and have stone 1 tile out of reach. Annex it, Harvest Resource! Late game that's 300+ production, twice. Still, I'd rather have him working as intended! I think it might be potentially be a real pain to fix though, as going through the modifiers, even if you change the modifiers for city size and allowed working size, it doesn't work in game, so it's potentially a real under the hood effort.