Tools Reference

Canonical names

Eight canonical names (defined in src/types.ts): health, plot, plot_series, diagram, geometry_3d, teaching, template, analysis. The MCP server exposes 24 unique tool entries in tools/list because the canonical names plus 16 legacy aliases are both registered (legacy names get mapped via src/compat.ts).

How routing works

Caller invokes tool by name (e.g. plot_multi) with JSON-RPC arguments
handleToolCall in src/index.ts L3205 calls lookupCompat
Legacy name resolves to canonical name + render format (e.g. plot_multi -> plot + render.format=png)
resolveLegacyName picks the actual legacy handler based on canonical name and render format
Handler in _legacyToolHandler (L3100) dispatches to buildSvgLinkData, pngLinkPayload, or buildTeachingTemplate

Tool categories (24 tools)

Category	Tools	Source
Health	`health`	`src/index.ts` L342, L709
Function plot (single)	`plot`, `plot_json`, `plot_png_link`	`src/index.ts` L347-372
Function plot (multi)	`plot_multi`, `plot_multi_json`, `plot_multi_png_link`	`src/index.ts` L374-399
Subplot grid	`multi_plot` (rows/cols with per-cell series)	`src/index.ts` L401-432
Custom series	`plot_series`, `plot_series_json`, `plot_series_png_link`	`src/index.ts` L434-458
Bar chart	`plot_bar_json` (categories+values shortcut)	`src/index.ts` L578-585
Force diagram	`force_diagram_link` (simple), `force_analysis_link` (rich, axes/components/resultant)	`src/index.ts` L461-486
Force template	`force_analysis_template_link` (incline/hanging/pulley/double_block/spring/spring_oscillator/pulley_group/horizontal)	`src/index.ts` L507-528, L902-1173
Circuit	`circuit_diagram_link` (freeform components+wires+stages), `circuit_template_link` (10 templates: series/parallel/switch_lamp/source_resistor/led_resistor/meter_loop/transistor_switch/relay_driver/buzzer_loop/opamp_follower)	`src/index.ts` L488-545
Venn	`venn_diagram_link` (2 or 3 sets with region labels)	`src/index.ts` L548-559
C memory	`c_memory_diagram_link` (blocks for pointer/struct/array)	`src/index.ts` L561-572
3D shape	`shape3d_link` (cube/sphere/cylinder/cone/vector3d, plus scatter3d/line3d/surface3d)	`src/index.ts` L574-576, L655-664
Teaching	`teaching_template_link` (single topic), `teaching_sequence_link` (multi-step sequence)	`src/index.ts` L587-604
Multi-image batch	`plot_multi_images` (batch of up to 8 plot jobs)	`src/index.ts` L3174-3190
Analysis	`analysis` (describe/corr/groupby) — Phase 1 placeholder	`src/index.ts` L3208, L695-706

Teaching topics (15)

From teachingToolProperties in src/index.ts L86-92:

parabola, definite_integral, tangent_derivative, fourier_series,
projectile_motion, simple_harmonic_motion, energy_conservation,
rc_charging, rlc_transient, incline_force, stress_strain, band_gap,
venn_probability, c_pointer_array, c_struct_layout

Each topic renders a single annotated plot (teaching_template_link) or a 2-3 step sequence (teaching_sequence_link). The sequences are hard-coded in buildTeachingSequence in src/index.ts L2830 — they stitch together multiple buildTeachingPlotPayload / sanitizeForceTemplatePayload calls with short URLs.

Render formats

From src/types.ts L9, RenderFormat = "png" | "svg" | "json" | "link" | "html". Behavior depends on tool:

png — returns hosted URL (e.g. https://.../png?d=...), PNG bytes served at URL
svg — inline SVG in the structuredContent field
json — full spec JSON + computed payload
link — short link via /s/{token} (8-char token in KV, 30-day TTL)
html — interactive 3D viewer (only for shape3d_link)

Annotations

From src/plot.ts L7-11, four kinds: vertical_line, point, label, area. All take a color; area additionally takes opacity. Used by plot_json and plot_series_json families.

Series transforms

From src/plot.ts L76-186, the transforms array on a series applies these operations in order:

Transform	Effect	Notes
`normalize`	minmax / zscore / maxabs	Not for hist/box/pie, or series with error bars
`smooth` / `rolling_average`	Centered moving average	Line series only; `window` default 3
`filter`	Keep points where `target op value`	ops: `>`, `>=`, `<`, `<=`, `==`
`downsample`	Uniform / LTTB subsampling	For huge series

Each emits warnings when skipped (e.g. smooth on scatter). Set args.debug = true to receive a debug object with per-stage traces.