The LLM had no way to know which profile names exist in the models
config section; a hallucinated name fell through to bare-name semantics
(default endpoint + bogus model) and failed at request time with API
400.
SubAgentTool now builds the model hint dynamically from config via
_model_names_hint(): description and the model parameter's JSON Schema
description both list the profile names, with the default profile
(api.default_model) marked. Empty or malformed models sections keep
the original wording untouched (zero breakage); exceptions degrade to
no hint.
README: tool table note, test count 293, new v3.4 changelog entry
summarizing the H1/H2/H3/M2 profile-hardening batch.
Tests: new TestM2SubAgentModelHint (5 cases); full suite 293 passed.
qing
77262f8c3a