diff --git a/.crow/backfill-flat-safety.yaml b/.crow/backfill-flat-safety.yaml
index 0db0735..cfb2be8 100644
--- a/.crow/backfill-flat-safety.yaml
+++ b/.crow/backfill-flat-safety.yaml
@@ -140,12 +140,11 @@ steps:
         from_secret: PGPASS
       REPO_RO_TOKEN:
         from_secret: REPO_RO_TOKEN
-      # uvr resolves bincraft's dependencies through the GitHub API, including
-      # the pat-s/cranlike@s3 fork. Unauthenticated it is rate limited, and the
-      # failure is not loud: uvr warns, falls back to the registry copy of
-      # cranlike, and the index write then dies on `unused argument (built =
-      # built)` because upstream has no such parameter. Intermittent by nature,
-      # since it depends on the rate-limit window.
+      # bincraft reads the DESCRIPTION of every new or replaced tarball from
+      # the CRAN mirror on raw.githubusercontent.com, and authenticates with
+      # this token when it is set. A slot whose published index cannot be read
+      # is re-read in full, ~25k requests, which the anonymous rate limit would
+      # cut short.
       GITHUB_PAT:
         from_secret: GITHUB_PAT
       GIT_USER: pat-s
diff --git a/.crow/reindex.yaml b/.crow/reindex.yaml
index 803d9a5..7db77fa 100644
--- a/.crow/reindex.yaml
+++ b/.crow/reindex.yaml
@@ -141,12 +141,11 @@ steps:
         from_secret: PGPASS
       REPO_RO_TOKEN:
         from_secret: REPO_RO_TOKEN
-      # uvr resolves bincraft's dependencies through the GitHub API, including
-      # the pat-s/cranlike@s3 fork. Unauthenticated it is rate limited, and the
-      # failure is not loud: uvr warns, falls back to the registry copy of
-      # cranlike, and the index write then dies on `unused argument (built =
-      # built)` because upstream has no such parameter. Intermittent by nature,
-      # since it depends on the rate-limit window.
+      # bincraft reads the DESCRIPTION of every new or replaced tarball from
+      # the CRAN mirror on raw.githubusercontent.com, and authenticates with
+      # this token when it is set. A slot whose published index cannot be read
+      # is re-read in full, ~25k requests, which the anonymous rate limit would
+      # cut short.
       GITHUB_PAT:
         from_secret: GITHUB_PAT
       GIT_USER: pat-s
diff --git a/.crow/weekly-rebuild-reindex.yaml b/.crow/weekly-rebuild-reindex.yaml
index 698f503..909722f 100644
--- a/.crow/weekly-rebuild-reindex.yaml
+++ b/.crow/weekly-rebuild-reindex.yaml
@@ -4,8 +4,8 @@
 # objects in place, so the slot's index still advertises the old MD5 and, for
 # anything that had been served from source, no Built stamp. Re-indexing from
 # inside a shard would mean three concurrent `upload_package_index()` calls on
-# one prefix: `cranlike::update_PACKAGES()` lists the live bucket, so an early
-# lister that uploads last publishes an index missing its siblings' work.
+# one prefix: each lists the live bucket, so an early lister that uploads last
+# publishes an index missing its siblings' work.
 #
 # So it happens exactly once per slot, here, after every shard has finished.
 # `runs_on: [success, failure]` keeps that true when a shard fails; only an
@@ -144,12 +144,11 @@ steps:
         from_secret: PGPASS
       REPO_RO_TOKEN:
         from_secret: REPO_RO_TOKEN
-      # uvr resolves bincraft's dependencies through the GitHub API, including
-      # the pat-s/cranlike@s3 fork. Unauthenticated it is rate limited, and the
-      # failure is not loud: uvr warns, falls back to the registry copy of
-      # cranlike, and the index write then dies on `unused argument (built =
-      # built)` because upstream has no such parameter. Intermittent by nature,
-      # since it depends on the rate-limit window.
+      # bincraft reads the DESCRIPTION of every new or replaced tarball from
+      # the CRAN mirror on raw.githubusercontent.com, and authenticates with
+      # this token when it is set. A slot whose published index cannot be read
+      # is re-read in full, ~25k requests, which the anonymous rate limit would
+      # cut short.
       GITHUB_PAT:
         from_secret: GITHUB_PAT
       GIT_USER: pat-s
diff --git a/README.md b/README.md
index 99d1143..9dceb42 100644
--- a/README.md
+++ b/README.md
@@ -103,11 +103,13 @@ Preview the selection without building or accessing storage or build metadata:
 
 ### Creating/Updating the PACKAGES Index Files
 
-Currently, the {cranlike} and {desc} packages only work with files on a local file system.
+Tools such as `tools::write_PACKAGES()` and {cranlike} only index files on a local file system.
 This is infeasible if the goal is to store binaries in S3.
 Storing binaries permanently on a disk-based file system would incur significantly higher costs, especially when operating in the cloud.
 
-Hence, [{cranlike}](https://devxy.gitlab.io/r-package-binaries/bincraft/) and [{desc}](https://github.com/pat-s/desc/tree/description-from-remote) were forked to handle files in S3 (through {s3fs}).
+Hence, `bincraft::upload_package_index()` builds the index from a listing of the slot in S3 (through {s3fs}).
+Each record is read from the package's CRAN `DESCRIPTION` on the GitHub mirror of CRAN, falling back to the `DESCRIPTION` inside the tarball for a package the mirror does not have.
+The previously published `PACKAGES.rds` serves as a cache, so only new or replaced tarballs are read.
 
 ### Resources