Return a canonical definition for a primitive Eurorack / synthesis concept and its relations to other concepts in the corpus.
Use this for VOCABULARY questions, not module questions — when the user is asking what a term means or how two terms relate, not which modules implement it. Typical shapes:
- "Is four-quadrant mult the same as through-zero AM?" → lookup_concept("four-quadrant mult")
- "What's the difference between a gate and a trigger?" → lookup_concept("gate")
- "Modular signal level vs line level — when does it matter?" → lookup_concept("modular signal level")
- "Are clock dividers just pulse counters?" → lookup_concept("clock divider")
- "Are polyphonic patch cables TRRRRRS?" → lookup_concept("polyphonic cable")
Lookup is case-insensitive across three axes, tried in order: the canonical id ("through-zero-fm"), the canonical label ("Through-Zero FM (TZFM)"), and any registered alias ("tzfm", "through zero fm"). Spaces and hyphens are matched literally; the lookup does NOT normalize whitespace beyond lowercasing. If the term doesn't match anything, the response includes up to 5 substring-matched suggestions.
Args:
- name (string, required, min length 2): the term to look up. Examples: "AM", "ring mod", "four-quadrant mult", "TZFM", "clock divider", "gate", "trigger".
Returns:
{
"concept": {
"id": "amplitude-modulation",
"label": "Amplitude Modulation (AM)",
"description": "A multiplication of two signals: the carrier...",
"aliases": ["am", "amplitude modulation", "amplitude mod"],
"related_concepts": [
{
"related_concept_id": "ring-modulation",
"related_concept_label": "Ring Modulation (RM)",
"relation_kind": "commonly_confused_with",
"note": "AM with a unipolar modulator preserves the carrier..."
},
...
],
"source_id": null,
"citation_url": "https://learningmodular.com/glossary/...",
"citation_quote": "Amplitude modulation is when..."
} | null,
"_meta": {
"query": "<the name argument verbatim>",
"matched_via": "id" | "label" | "alias" | "none",
"suggestions": [
{ "id": "...", "label": "...", "matched_via": "alias", "matched_text": "..." }
],
"feedback_hint": "...?"
}
}
Relation kinds:
- "related_to" — see-also link (default; symmetric in spirit).
- "subtype_of" — X is a specific case of Y (RM ⊂ AM, TZFM ⊂ linear FM).
- "inverse_of" — X is the opposite of Y (clock-divider ↔ clock-multiplier).
- "commonly_confused_with" — they're distinct, but people conflate them
(gate vs trigger, AM vs RM, modular level vs line level).
When to cite: every concept carries either source_id or citation_url + citation_quote. Surface the citation when the answer affects a decision (e.g. "the corpus cites learningmodular.com — TRS cables are physically the same connector whether carrying balanced mono or unbalanced stereo; only the destination determines the role").
When the result is null and suggestions are provided, present 2–3 closest suggestions to the user. If none look right, the corpus genuinely doesn't carry that concept — call report_gap with kind="missing_field" and tool_name="lookup_concept" naming the term and its expected definition.
Connector