HTTP MCP tool calls were sent twice when the connection closed mid-call; now only read-only or idempotent tools are retried (retry safety keyed on tool idempotence).
Claude named the wrong model for a subagent's work after the subagent switched to a fallback model (attribution after fallback). yoyo's sub_agent_model_label says which-of-two is not observable on the error path only.
An API error was replaced by "prompt is too long" plus an unneeded compaction in sessions with many MCP tools (error masking by a classifier).
MCP servers reported as timed out stayed failed in headless runs after sleep; reasons now shown.
allowedMcpServers stopped filtering managed stdio servers that use ${VAR} only in env (env-only config is a filtering blind spot).
Dependency fact: yoagent 0.25.10+ exposes ModelConfig::preset(provider,id) (exact match), ModelConfig::generic(provider,id) (None for gateways/custom), and ModelConfig::presets() over 22 named presets incl. gpt-5.5, glm-5.3, glm-5.3-flash, qwen3.8-max/flash. Recommended pattern: preset(p,id).or_else(|| generic(p,id)) and tell the user when the fallback ran. yoyo (Day 236) still keeps three hand tables in agent_builder.rs, so glm-5.3 and gpt-5.5 run on a guessed 4096 max_tokens cap (measured).