Fisherman's Pocket Guide

Informational accessories work from your inventory, a Void Bag or a social slot, so this costs nothing but a square of storage. There is no reason to hand it a real accessory slot unless you specifically want a modifier on it. If you would rather have the Weather Radio or the Sextant, Shimmer trades between the three, so a duplicate from the Angler is never wasted.

Fishing power moves with your rod, your bait, the weather, the time of day and the moon phase, and none of that is visible anywhere else. This is the fastest way to check whether a change you made helped. It doubles as a pool checker: if the water you are standing over is too small to fish in, it says so plainly instead of quietly returning nothing. That message alone saves a lot of confusion when an artificial lake comes out a few buckets short.

Bait a Truffle Worm and the readout switches to a warning rather than a number. That is the game telling you Duke Fishron is one bite away, not a bug. Worth remembering if you keep worms in your inventory and fish the ocean casually.