All 50 skills × ~150 tokens each were loaded the moment this pane existed. Scroll, scan, click the one you think is right — the meter was paid up front either way.
Only the root index is loaded (~150 tokens). Click a node to “Read” it: that injects its layer — its children appear, the breadcrumb grows, the meter counts the node you entered. Nothing you don't enter is ever loaded.
Flat paid for all 50 before you looked; the tree paid for the path you walked. flat: 7,500 tokens (50 skills, up front) · tree: 150 tokens (1 node entered)
Flat exposure costs O(#tools): every definition is in context before
the first request, so the bill grows linearly with the size of the library
whether or not a skill is ever used. Descent costs O(depth): one node's
layer per level walked, bounded by the depth of the tree rather than the size of
the library. Reaching csv-cleaner here takes four nodes
(0 → 0.1 data → 0.1.1 tabular → csv-cleaner)
≈ 600 tokens, against 7,500 paid up front on the left. The argument and its
calibration against the platform's own published measurement are in
Paper 1, §4 and
Figure 1; why a depth-one skill
library is a flat forest is §6.