Scouting the docs

SuperCollider is a large language with a small vocabulary of obvious names and a large one of non-obvious ones. SinOsc is what you expect; Decay2, LeakDC, DetectSilence, LocalIn and RandSeed are not. And a UGen's argument order is not guessable: RLPF.ar(in, freq, rq) and BPF.ar(in, freq, rq) look alike, MoogFF.ar(in, freq, gain) does not.

The install ships its own reference — on the machine this was written on, 1146 .schelp files under HelpSource/. That is the authority. sc_help reads it.

The four actions

Action	Use it for
search	"Is there a UGen for a moving filter?" — ranked sections with excerpts
answer	"How do I make a reverb?" — the three best sections as evidence
class	"What are PlayBuf's arguments?" — one page, by name or path
index / refresh	Whether an index exists, and rebuilding it after an install changed

Search before you assume

sc_help action=search query="resonant low pass filter"

That returns BLowPass and BLowPass4 at the top — measured on a real install — which is the point: you could not have guessed those names, and now you have them. The result names the section and the file each hit came from, so you can go and read the whole page once a hit looks right. Search expands a small synonym table, which is why "guitar" finds Pluck and DwgPluck, and "drum" finds Impulse and Decay2. Search with a class name or a descriptive phrase not a question — see the table at the bottom of this page for why.

Read the page for its arguments

sc_help action=class name=RLPF

Argument names are what sc_nodes action=set needs, and they are what a SynthDef body's |...| must match. Reading the page costs one call and removes the guess entirely.

A class page is reachable by name (RLPF) or by path (Guides/Server-Guide, Reference/Server-Command-Reference, Overviews/UGens).

Ask for evidence before writing a long answer

sc_help action=answer query="Pbind dur scheduling"

It returns quoted sections rather than a synthesis. That is deliberate: you write the answer, it supplies the ground truth. It runs the same ranker as search with three results, so the same advice applies — a list of names, not a sentence.

What is in the tree

Folder	What is there
Classes/	one page per class — the bulk of it, and the one you want most often
Guides/	longer tutorials: Server-Guide, ClientVsServer, Patterns, Tour-of-UGens
Reference/	reference material: Server-Command-Reference (the OSC dictionary), SCDoc-Syntax
Overviews/	the conceptual map: UGens, Operators, Patterns
Tutorials/	the book: Getting-Started, Mark Polishook Tutorial

Reference/Server-Command-Reference.schelp is the file to read when you need an OSC command by name — /s_new, /n_set, /d_load, /g_queryTree — because inventing one that sounds plausible is a wasted turn.

What a .schelp file looks like

Every page is a run of key:: body sections:

class:: RLPF
summary:: Resonant low pass filter
categories:: UGens>Filters>Linear

description::
An RLPF is a resonant low pass filter...

classmethods::
method::ar
argument::in
The input signal.
argument::freq
Cutoff frequency in Hertz.

examples::
code::
{ RLPF.ar(Saw.ar(200), 800, 0.1) * 0.1 }.play;
::

So title:: is the page's own name, class:: the class it documents, description:: the prose, method:: and argument:: the API, and examples:: the runnable part. link::Classes/SinOsc:: is a cross-reference, and the search index scores those: a query naming SinOsc will surface FSinOsc too, because the pages link to each other.

The examples:: sections are the best source of working code. When you are unsure how to use something, search for it and read the example rather than composing from memory.

When to reach for it, concretely

Situation	Call
You are about to write \someKey in a Pbind and you are not sure	sc_help action=class name=Pbind
A UGen failed with not understood	sc_help action=search query="<the name you used>"
You need the right argument list for a filter	sc_help action=class name=<ClassName>
You need an OSC address	sc_help action=class name=Reference/Server-Command-Reference
The user asks "what does X do"	sc_help action=answer query="X"
Search returns nothing for a real thing	sc_help action=index, then refresh — the tree may have moved

Search returns nothing only when the words are wrong, not when the concept is missing. Try the class name you think it is, then a broader term ("filter", "envelope", "buffer"), then the Overviews page for the area.

A whole sentence is a bad query. The ranker scores each token independently and adds the weights up, with no stemming and no notion of a phrase, so the words a question is made of — "make", "how", "do", "a", "with" — are scored just like the class name. Measured on a real install:

Query	What it finds
SinOsc	the SinOsc page, first
sine oscillator	FBSineC, because both words are in its page
how do I make a sine oscillator	SCDocSyntax, which is about the help format

So search for the name, not the question: SinOsc, RLPF, PlayBuf, Env.asr. If you cannot name it yet, search the noun you are sure of ("envelope", "filter", "granular") and read the Overviews or Guides page that comes back, which is where the names are listed.