diff --git a/src/commands/index.js b/src/commands/index.js
index 98d5664..7e8d439 100644
--- a/src/commands/index.js
+++ b/src/commands/index.js
@@ -12,12 +12,16 @@ module.exports = [
     topic: 'data.influent',
     aliases: ['influent', 'setInfluent'],
     payloadSchema: { type: 'any' },
+    // Compound payload `{F, C: [...]}` — registry-level units normalisation is
+    // skipped (the handler converts per-field internally; flow=m3/h, conc=mg/L).
+    description: 'Push the influent stream (payload: {F: flow m3/h, C: [concentrations mg/L]}).',
     handler: handlers.dataInfluent,
   },
   {
     topic: 'child.register',
     aliases: ['registerChild'],
     payloadSchema: { type: 'string' },
+    description: 'Register a child node (typically a measurement) with this settler.',
     handler: handlers.childRegister,
   },
 ];