diff --git a/src/commands/index.js b/src/commands/index.js
index 83f491c..24c132b 100644
--- a/src/commands/index.js
+++ b/src/commands/index.js
@@ -14,27 +14,32 @@ module.exports = [
     // Toggle — payload is ignored. `any` keeps the registry validator happy
     // for legacy callers that ship trigger payloads of various shapes.
     payloadSchema: { type: 'any' },
+    description: 'Toggle the built-in simulator on / off.',
     handler: handlers.setSimulator,
   },
   {
     topic: 'set.outlier-detection',
     aliases: ['outlierDetection'],
     payloadSchema: { type: 'any' },
+    description: 'Toggle / configure outlier detection on the measurement pipeline.',
     handler: handlers.setOutlierDetection,
   },
   {
     topic: 'cmd.calibrate',
     aliases: ['calibrate'],
     payloadSchema: { type: 'any' },
+    description: 'Trigger a one-shot calibration of the measurement.',
     handler: handlers.calibrate,
   },
   {
     topic: 'data.measurement',
     aliases: ['measurement'],
-    // Mode-dispatched: digital expects object, analog expects number/numeric
-    // string. The handler validates per-mode (the registry-level typeof
-    // check would reject one of the two valid shapes).
+    // Mode-dispatched: digital expects object (per-channel), analog expects
+    // number/numeric string in the configured Channel scaling units. Units
+    // are mode-dependent and resolved inside the handler — no registry-level
+    // `units` field.
     payloadSchema: { type: 'any' },
+    description: 'Push a raw measurement (analog: number; digital: per-channel object).',
     handler: handlers.dataMeasurement,
   },
 ];