rb209-nutrient-planning

RB209 Nutrient Planning

Produce a fertiliser recommendation for a UK field with the rb209_* MCP tools. The one calculation tool is rb209_recommendation_recommendations (a POST taking { body: <DataInput> }). Everything else is lookups that give you the integer IDs the DataInput needs.

Golden rules — read first

1. Interview the user before calling anything. Do not invent field details. A recommendation depends on real facts about a real field (crop, soil, location, previous crop, manures, soil-test results). If you don't have one of these, ask the user a short, specific question — never guess a crop, a yield, or a soil type. See Phase 1.
2. Resolve every ID from a lookup tool. IDs like cropTypeId, soilTypeId, swardTypeId are API-specific integers. Look them up; never hard-code them from memory. Show the user the options when a choice is theirs to make.
3. Copy the shape of a known-good request. This repo has two real, accepted DataInput/response pairs — mirror the one matching your field type and only swap in the values you gathered:
   • Arable: test/fixtures/RecommendationsSampleInput.json (+ …Sample.json) — winter barley, England & Wales.
   • Grass: test/fixtures/RecommendationsGrassInput.json (+ …GrassSample.json) — first-cut silage plus grazing, England & Wales.
4. If the API returns a validation error, read it — the field is named. The error tells you exactly what to fix. See Troubleshooting for the common ones and their fixes.
5. Be efficient — a whole recommendation is usually ~6–10 tool calls, not 30. Avoid these common wasted calls:
   • One recommendation call returns all nutrients. Set every nutrient you want to true in the single nutrients object and call rb209_recommendation_recommendations once. Do not call it per nutrient or re-call it to "check" — N, P₂O₅, K₂O, MgO, SO₃ and lime all come back together.
   • Don't look fieldType up — it's fixed: 1 = Arable & Horticulture, 2 = Grassland, 3 = Both.
   • No soil analysis? Send "soilAnalyses": [] and skip all soil methodology/index lookups. The engine applies RB209 default indices; you do not need rb209_soil_methodologies…, rb209_soil_nutrient_index…, or any index tool. (Those T04 "not found" errors mean you're fetching indexes you don't need.)
   • Don't use rb209_recommendation_calculate_nutrient_offtake or nutrient target-index tools for a standard field recommendation — the main recommendation call already does that maths.