diff --git a/skills/apk-reverse/references/toolchain.md b/skills/apk-reverse/references/toolchain.md
index 73ee17c..13e3dee 100644
--- a/skills/apk-reverse/references/toolchain.md
+++ b/skills/apk-reverse/references/toolchain.md
@@ -56,6 +56,13 @@ python scripts/rasc_build.py --build            # needs git + rustup; ~2 min
 python scripts/rasc_build.py --verify app.apk   # compares class sets against droidasc, fails on a difference
 ```
 
+**It is a registered capability, so G2 does not have to guess:** `doctor.py` reports `dex_index_rust`
+as `OK` when a binary is present (PATH, `APKREV_TOOLS`, or the work-area path `rasc_build.py` builds
+into) and `BLOCKED` with that build command as the next action when it is not — alongside
+`dex_index_python` for the `pip install` route. A machine with neither is not stuck: the Python
+indexer is one command away, and the two are cross-checked against each other by
+`rasc_build.py --verify`.
+
 **The one thing to know before trusting its `getclass`:** on an `enum` whose constants override an
 abstract method, the outer class is printed as a bare constant list and the per-constant bodies are
 **not inlined** — no warning, and none in the Python tool either, because both leave those bodies in
diff --git a/skills/apk-reverse/scripts/capabilities.py b/skills/apk-reverse/scripts/capabilities.py
index 8e3d80a..e5b8a15 100644
--- a/skills/apk-reverse/scripts/capabilities.py
+++ b/skills/apk-reverse/scripts/capabilities.py
@@ -190,6 +190,27 @@ ATOMS = {
         'est_minutes': 5,
         'basis': 'unverified',
     },
+    'tool:rasc': {
+        'name': 'rasc (Rust ASC: whole-APK dex index)',
+        'kind': 'tool',
+        'tool': 'rasc',
+        'install': 'it ships no artifact -- run `python scripts/rasc_build.py --build` '
+                   '(needs git plus rustup; on Windows the GNU host toolchain also needs a '
+                   '64-bit MinGW-w64 gcc), or set RASC to an existing binary',
+        'est_minutes': 5,
+        # Measured here: a clean clone built in 117 s once the toolchain existed, which is the
+        # toolchain-acquisition cost on top. The toolchain itself is the larger part and is
+        # machine-specific, so the estimate covers the build step and says so.
+        'basis': 'measured',
+    },
+    'tool:droidasc': {
+        'name': 'droidasc (Python ASC: whole-APK dex index)',
+        'kind': 'tool',
+        'tool': 'droidasc',
+        'install': 'pip install droidasc',
+        'est_minutes': 1,
+        'basis': 'measured',
+    },
     'tool:apktool': {
         'name': 'apktool (resource round-trip)',
         'kind': 'tool',
@@ -317,6 +338,24 @@ GATE_FILES = {
 # `depends_on` is expanded recursively, so a prerequisite's blockers are inherited.
 
 CAPABILITIES = {
+    'dex_index_rust': {
+        'name': 'Whole-APK dex index and single-class decompilation (rasc, the Rust ASC)',
+        'required': ['python39', 'tool:rasc'],
+        'optional': [],
+        'scripts': ['rasc_build.py'],
+        'note': 'the fastest indexer this kit documents -- same answers as droidasc on '
+                'both archives measured, 4-15x quicker -- but it ships no prebuilt '
+                'artifact, so `rasc_build.py --build` is how a machine acquires it. Its '
+                'outer-class view of an enum does not inline the constant bodies; the '
+                'subclasses decompile fine (references/rasc-and-droidsaw.md)',
+    },
+    'dex_index_python': {
+        'name': 'Whole-APK dex index and single-class decompilation (droidasc, the Python ASC)',
+        'required': ['python39', 'tool:droidasc'],
+        'optional': [],
+        'note': 'one `pip install droidasc` away, and the cross-check for the Rust one: '
+                'their class-definition sets are compared in scripts/rasc_build.py --verify',
+    },
     'static_dex': {
         'name': 'Static dex / zip / strings analysis',
         'required': ['python39'],
@@ -520,6 +559,18 @@ class Probe:
         if name in self._tool_cache:
             return self._tool_cache[name]
         hit = shutil.which(name)
+        if not hit and name == 'rasc':
+            # rasc ships no artifact, so a machine that followed this kit's own build step has it
+            # under the repository's ignored work area rather than on PATH. Accepting that location
+            # keeps the capability table from reporting BLOCKED at an agent that already did the
+            # work -- the same reasoning as APKREV_TOOLS, for the one tool whose install step is a
+            # build (scripts/rasc_build.py).
+            for cand in (os.path.join(REPO_ROOT, 'tools', '_work', 'rust', 'target', 'release',
+                                      'rasc' + ('.exe' if os.name == 'nt' else '')),
+                         os.environ.get('RASC', '')):
+                if cand and os.path.isfile(cand):
+                    hit = cand
+                    break
         if not hit:
             exts = [''] if os.name != 'nt' else ['.exe', '.bat', '.cmd', '.ps1', '']
             for d in extra_tool_dirs():
diff --git a/skills/apk-reverse/scripts/doctor.py b/skills/apk-reverse/scripts/doctor.py
index 90512c6..88645da 100644
--- a/skills/apk-reverse/scripts/doctor.py
+++ b/skills/apk-reverse/scripts/doctor.py
@@ -561,7 +561,10 @@ def main():
                               'blocked': counts['blocked'], 'unknown': counts['unknown']},
         }
         print(json.dumps(payload, indent=2, ensure_ascii=False))
-        print('RESULT=%s' % token)
+        # No `RESULT=` line on this path: appending one makes the stream invalid JSON for a caller
+        # doing `--json | jq` or `json.loads(stdout)`, which is what `--json` is for. The status is a
+        # field in the document, and the exit code carries the same meaning. (Same defect that was
+        # found in check_commands.py, and it was found here by trying to parse this output.)
         return code
 
     print('=' * 74)