diff --git a/packages/backend/src/server/SkRateLimiterService.md b/packages/backend/src/server/SkRateLimiterService.md
index 762f8dfe14..fb007538fa 100644
--- a/packages/backend/src/server/SkRateLimiterService.md
+++ b/packages/backend/src/server/SkRateLimiterService.md
@@ -12,6 +12,11 @@ SkRateLimiterService is not quite plug-and-play compatible with existing call si
 Instead, the returned LimitInfo object will have `blocked` set to true.
 Callers are responsible for checking this property and taking any desired action, such as rejecting a request or returning limit details.
 
+Rate limit factors are also handled differently.
+Instead of providing an optional parameter for callers, SkRateLimiterServer accepts an `MiUser` parameter that is used to compute the factor directly.
+If a user is not available (such as for unauthenticated callers), then the Role Template factor is used instead.
+To avoid confusion, the `factor` parameter has been removed entirely and is now an implementation detail.
+
 ## Headers
 
 LimitInfo objects (returned by `SkRateLimitService.limit()`) can be passed to `rate-limit-utils.sendRateLimitHeaders()` to send standard rate limit headers with an HTTP response.
diff --git a/packages/backend/src/server/api/SkRateLimiterService.ts b/packages/backend/src/server/api/SkRateLimiterService.ts
index 70103222f3..038f12cb25 100644
--- a/packages/backend/src/server/api/SkRateLimiterService.ts
+++ b/packages/backend/src/server/api/SkRateLimiterService.ts
@@ -40,7 +40,15 @@ export class SkRateLimiterService {
 	}
 
 	/**
-	 * Check & increment a rate limit for a client
+	 * Check & increment a rate limit for a client.
+	 *
+	 * If the client (actorOrUser) is passed as a string, then it uses the default rate limit factor from the role template.
+	 * If the client (actorOrUser) is passed as an MiUser, then it queries the user's actual rate limit factor from their assigned roles.
+	 *
+	 * A factor of zero (0) will disable the limit, while any negative number will produce an error.
+	 * A factor between zero (0) and one (1) will increase the limit from its default values (allowing more actions per time interval).
+	 * A factor greater than one (1) will decrease the limit from its default values (allowing fewer actions per time interval).
+	 *
 	 * @param limit The limit definition
 	 * @param actorOrUser authenticated client user or IP hash
 	 */