diff --git a/plugins/ruff-format/.claude-plugin/plugin.json b/plugins/ruff-format/.claude-plugin/plugin.json
index d6cce7c54..6798e7352 100644
--- a/plugins/ruff-format/.claude-plugin/plugin.json
+++ b/plugins/ruff-format/.claude-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/claude-code-plugin-manifest.json",
   "name": "ruff-format",
-  "version": "0.4.3",
+  "version": "0.4.4",
   "description": "Auto-format and lint Python on edit via Ruff, only when a Ruff config governs the repo — using the consuming repo's own Ruff config.",
   "author": {
     "name": "Melodic Software",
diff --git a/plugins/ruff-format/CHANGELOG.md b/plugins/ruff-format/CHANGELOG.md
index 87b70b890..63e4dbdc6 100644
--- a/plugins/ruff-format/CHANGELOG.md
+++ b/plugins/ruff-format/CHANGELOG.md
@@ -3,6 +3,19 @@
 All notable changes to the `ruff-format` plugin are documented here. Format follows
 [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); this plugin uses semantic versioning.
 
+## [0.4.4]
+
+### Documented
+
+- Documented a known limitation of the pyproject.toml opt-in gate: the
+  line-anchored `[tool.ruff]` header check does not recognize the equivalent
+  TOML inline-table form (`[tool]` + `ruff = { ... }`), which Ruff itself
+  honors. Such a repo is treated as un-configured and the hook skips — fails
+  safe (a missed opt-in, never a wrong edit). Added a test case locking in the
+  documented (skip) behavior. No gate logic change: a robust fix needs real
+  TOML parsing, which is out of scope for this hook (see the hook's inline
+  comment for the full rationale).
+
 ## [0.4.3]
 
 ### Fixed
diff --git a/plugins/ruff-format/README.md b/plugins/ruff-format/README.md
index 9954851d7..d04d6181c 100644
--- a/plugins/ruff-format/README.md
+++ b/plugins/ruff-format/README.md
@@ -17,7 +17,11 @@ own and runs only when your repo has opted into Ruff.
   same discovery Ruff itself uses (a `pyproject.toml` without `[tool.ruff]` is
   ignored, exactly as Ruff ignores it). A repo without a Ruff config is left
   untouched rather than rewritten to Ruff's built-in defaults, so the plugin
-  never imposes a style you did not choose.
+  never imposes a style you did not choose. **Known limitation:** a
+  `pyproject.toml` that expresses this as a bare `[tool]` header with an inline
+  table (`[tool]` + `ruff = { ... }`) is not recognized, even though Ruff
+  itself honors that form — such a repo is treated as un-configured and the
+  hook skips (fails safe: a missed opt-in, never a wrong edit).
 - **Fix + format on edit.** `ruff check --fix` applies safe fixes (never
   `--unsafe-fixes`) and `ruff format` formats in place. Residual diagnostics
   are reported but not auto-applied.
diff --git a/plugins/ruff-format/hooks/ruff-format.sh b/plugins/ruff-format/hooks/ruff-format.sh
index 3bf438c99..c7c4fc61e 100755
--- a/plugins/ruff-format/hooks/ruff-format.sh
+++ b/plugins/ruff-format/hooks/ruff-format.sh
@@ -128,6 +128,17 @@ root="$(cd "$REPO_ROOT" 2>/dev/null && pwd)" || root=""
 # pyproject.toml). A pyproject.toml counts only when it carries a [tool.ruff]
 # section (or a [tool.ruff.*] subtable) — Ruff skips it for discovery otherwise.
 # Absence of any config is the opt-out: the file is left untouched.
+#
+# Known limitation: this line-anchored grep only recognizes the `[tool.ruff]`
+# header form. TOML also allows the equivalent config as an inline table under
+# a bare `[tool]` header (`[tool]` + `ruff = { ... }`), which Ruff itself does
+# honor — a repo using that form is treated as un-configured here and the gate
+# skips it. Fails safe (a missed opt-in, never a wrong edit); left undetected
+# rather than heuristically matched because a robust check needs real TOML
+# parsing (inline tables span lines, nest arbitrarily, and the `ruff` key can
+# appear in any order under `[tool]`), and a multi-pass grep risks a false
+# positive from an unrelated `ruff = "..."` key in a different table or a
+# commented-out line.
 CONFIG_FOUND=""
 dir="$FILE_DIR_POSIX"
 while [[ -n "$dir" ]]; do
diff --git a/plugins/ruff-format/hooks/ruff-format.test.sh b/plugins/ruff-format/hooks/ruff-format.test.sh
index aeb24d699..9b59077eb 100755
--- a/plugins/ruff-format/hooks/ruff-format.test.sh
+++ b/plugins/ruff-format/hooks/ruff-format.test.sh
@@ -159,6 +159,22 @@ RC=$?
 if [[ $RC -eq 0 ]]; then ok "pyproject with [tool.ruff] -> exit 0"; else fail "pyproject opt-in exit $RC"; fi
 if grep -q 'x = 1' "$REPO_PT/opt.py"; then ok "pyproject with [tool.ruff] -> file formatted"; else fail "pyproject opt-in -> not formatted: $(cat "$REPO_PT/opt.py")"; fi
 
+# --- Case 1d: pyproject.toml with [tool] inline-table form does NOT opt in ---
+# Known limitation (documented in the hook and README): the line-anchored gate
+# only recognizes the `[tool.ruff]` header form. A bare `[tool]` header with
+# `ruff = { ... }` as an inline table is equivalent TOML that Ruff itself does
+# honor, but the gate does not detect it — fails safe (missed opt-in, not a
+# wrong edit) rather than heuristically pattern-matching it.
+REPO_PI="$WORK/pyproject-inline"
+new_ruff_repo "$REPO_PI" NO_CONFIG
+printf '[project]\nname = "t"\n\n[tool]\nruff = { line-length = 88 }\n' >"$REPO_PI/pyproject.toml"
+printf 'x=1\n' >"$REPO_PI/inline.py"
+BEFORE_PI="$(cat "$REPO_PI/inline.py")"
+OUT=$(run_hook "$REPO_PI/inline.py")
+RC=$?
+if [[ $RC -eq 0 && -z "$OUT" ]]; then ok "pyproject with [tool] inline-table ruff -> exit 0, silent (known limitation)"; else fail "inline-table pyproject opted in (rc=$RC out=$OUT)"; fi
+if [[ "$(cat "$REPO_PI/inline.py")" == "$BEFORE_PI" ]]; then ok "pyproject with [tool] inline-table ruff -> file left untouched"; else fail "inline-table pyproject -> file was rewritten"; fi
+
 # --- Case 2: gate ON + clean file -> exit 0, empty stdout --------------------
 REPO="$WORK/consumer"
 new_ruff_repo "$REPO"