diff --git a/packages/svelte/src/internal/shared/types.d.ts b/packages/svelte/src/internal/shared/types.d.ts
index 1bcdd36f97..8365b529f9 100644
--- a/packages/svelte/src/internal/shared/types.d.ts
+++ b/packages/svelte/src/internal/shared/types.d.ts
@@ -11,10 +11,19 @@ export type Snapshot<T> = ReturnType<typeof $state.snapshot<T>>;
 
 export type MaybePromise<T> = T | Promise<T>;
 
+/** Decode a value. The value will be whatever the evaluated JavaScript emitted by the corresponding {@link Encode} function evaluates to. */
 export type Decode<T> = (value: any) => T;
 
+/** Encode a value as a string. The string should be _valid JavaScript code_ -- for example, the output of `devalue`'s `uneval` function. */
 export type Encode<T> = (value: T) => string;
 
+/**
+ * Custom encode and decode options. This must be used in combination with an environment variable to enable treeshaking, eg:
+ * ```ts
+ * import { BROWSER } from 'esm-env';
+ * const transport: Transport<MyType> = BROWSER ? { decode: myDecodeFunction } : { encode: myEncodeFunction };
+ * ```
+ */
 export type Transport<T> =
 	| {
 			encode: Encode<T>;
@@ -25,28 +34,25 @@ export type Transport<T> =
 			decode: Decode<T>;
 	  };
 
+/** Make the result of a function hydratable. This means it will be serialized on the server and available synchronously during hydration on the client. */
 export type Hydratable = {
-	<T>(key: string, fn: () => T, options?: { transport?: Transport<T> }): T;
+	<T>(
+		/**
+		 * A key to identify this hydratable value. Each hydratable value must have a unique key.
+		 * If writing a library that utilizes `hydratable`, prefix your keys with your library name to prevent naming collisions.
+		 */
+		key: string,
+		/**
+		 * A function that returns the value to be hydrated. On the server, this value will be stashed and serialized.
+		 * On the client during hydration, the value will be used synchronously instead of invoking the function.
+		 */
+		fn: () => T,
+		options?: { transport?: Transport<T> }
+	): T;
+	/** Get a hydratable value from the server-rendered store. If used after hydration, will always return `undefined`. Only works on the client. */
 	get: <T>(key: string, options?: { decode?: Decode<T> }) => T | undefined;
+	/** Check if a hydratable value exists in the server-rendered store. */
 	has: (key: string) => boolean;
+	/** Set a hydratable value. Only works on the server during `render`. */
 	set: <T>(key: string, value: T, options?: { encode?: Encode<T> }) => void;
 };
-
-export type Resource<T> = {
-	then: Promise<Awaited<T>>['then'];
-	catch: Promise<Awaited<T>>['catch'];
-	finally: Promise<Awaited<T>>['finally'];
-	refresh: () => Promise<void>;
-	set: (value: Awaited<T>) => void;
-	loading: boolean;
-	error: any;
-} & (
-	| {
-			ready: false;
-			current: undefined;
-	  }
-	| {
-			ready: true;
-			current: Awaited<T>;
-	  }
-);