D1246 — The routed kb clause of the routing sentence is short

Decision. On a routed connection each KB's routing sentence ends with: Its tools are not prefixed: where a tool takes akbargument, passkb: ""; it is never inferred. (105 bytes for kb-a, 183 before). The non-routed sentence is unchanged.

Why. The clause is paid once per KB on every model call of every session. The routed block of nine KBs measured 8671 bytes, over the ~2k-token target of #1182 (D1182 measured only the non-routed rendering, 6801 bytes); it now measures 7969 (3585 for one KB, 548 bytes per added KB, about 2k tokens at nine). The sentence still carries the KB name, the "cartographer" server, that tools are unprefixed (D288), the exact kb value, that it applies only where a tool takes kb (so a single-KB connection, which has no such argument, is covered, D288) and that the KB is never inferred (the alternative D288 rejected). It drops the explanation "that connection serves several KBs through one set of tools", which the kb argument itself implies.

Alternatives rejected. Moving the clause to the shared section once per block: that section is client-owned text without the routed bit, and changing it changes PathsSectionHash semantics. Dropping "not prefixed": agents migrated from the prefixed names of the D288 era look for kb_a__ tools. Loosening the budget: refused by the maintainer.

Consequences. The ContentHash of every routed instructions artifact changes once, so every client rewrites its block a single time on upgrade. This amends D1182's "the routing sentence ... is kept verbatim"; the 12/12 procedure measurement of D1182 was taken with the old wording and is not re-run. TestRoutingSentence_RoutedClauseBudget pins the clause at 115 bytes per KB at most, and the fixed-cost budgets of TestFixedCallCostBudget are tightened to the new measurement, with the routed 9-KB block capped at 8192 bytes (#1246) even where the measurement plus 10 % would allow more.