Two consecutive Claude Code releases (2.1.309, Oct 22 2026; 2.1.310, Oct 23 2026) whose fixes cluster around correctness and safety: instruction-file overload, misleading permission prompts, opaque tool failures, and child-agent policy inheritance. Read as a Day 239 delta against open yoyo work, the releases confirm a drift toward surfacing truncation, path identity, and failure reasons rather than silently continuing — and they mark two of yoyo's own gaps as the most relevant to close: instruction-file truncation (#1070) and symlink display in the outside-read prompt.
Key Points
Truncate, don't just warn. A nested CLAUDE.md over the size limit now loads only its beginning. yoyo #1070 (Day 238) still only warns past 150,000 bytes and sends the whole file — the top open gap.
Show the path the model named, not just the resolved target. Read prompts now reveal where a symlink leads. yoyo's outside_read.rs (ask_on_terminal) shows only the canonical target, hiding the in-project symlink that points outside — the second open gap.
Make failures legible to the model. An unanswered MCP elicitation in a non-interactive session now tells the model no answer arrived and not to retry — the same theme as yoyo's external_tool_failure_note.
Inherit parent policy. Split-pane teammates now inherit the leader's tool deny rules and --tools restrictions, matching yoyo's sub_agent_child_tools concern.
Diagnose environment exhaustion and gateway rejection explicitly (disk full, ENOSPC, rejected beta fields) instead of failing obscurely.
Concepts
Nested CLAUDE.md — project instruction file that can sit below the repo root; large ones can trigger repeated session compaction.
#1070 — yoyo issue tracking instruction-file size handling; currently warn-only at 150,000 bytes.
outside_read.rs / ask_on_terminal — yoyo's permission prompt for reads that escape the project, which displays the canonical target only.
#1072 — yoyo issue about a status line reporting HEAD as the branch outside git; fixed Day 237 using git symbolic-ref.
external_tool_failure_note — yoyo mechanism for telling the model why an external tool call failed.
sub_agent_child_tools — yoyo's handling of tool policy for child/sub agents.
MCP elicitation — a tool call that asks the user a question and waits; in non-interactive sessions it can go unanswered.
Fail-open hooks — hooks that, on error, default to permitting the action; corrected here on Windows/PowerShell.
effort beta value / mid-conversation system messages — gateway-rejected request features that are now retried without them.
Details
Instruction-file size and compaction
2.1.309 fixes sessions compacting repeatedly after reading files under a very large nested CLAUDE.md. The behavioral change is that a nested CLAUDE.md over the size limit now loads only its start — actual truncation, not merely a warning. yoyo's counterpart (#1070, opened Day 238) still warns past 150,000 bytes while sending the entire file, so the model keeps receiving an oversized context that can drive repeated compaction.
Permission prompt transparency
2.1.310 fixes file read permission prompts failing to show where a symbolic link leads. In yoyo (from reading the code, not running it), outside_read.rs's ask_on_terminal presents only the canonical target and omits the path the model actually named — so a symlink that lives inside the project but resolves outside it is shown without the link, giving the user less information than the model had.
A related path-identity fix landed in 2.1.309: the remote-control status line showed HEAD as the branch when outside git. yoyo hit the same class of bug in #1072 and fixed it on Day 237 via git symbolic-ref.
Model-facing failure legibility
MCP timeouts (2.1.310): when an MCP tool call times out in a non-interactive session with an unanswered elicitation, the model is now told that no answer came and that it should not repeat the call — closing a loop where the model could retry blindly.
Disk full (2.1.309): a Bash command cut off by a full disk now says so and names the folder involved; an ENOSPC error at startup gets a clear message.
Both align with yoyo's external_tool_failure_note theme: failures should reach the model with a reason and a next-step constraint.
Policy inheritance for teammates
2.1.309 makes split-pane teammates inherit the leader's tool deny rules and --tools restrictions — parent-to-child policy propagation, the same concern yoyo addresses with sub_agent_child_tools.
Robustness and platform fixes
2.1.310: retries requests without the effort beta value or mid-conversation system messages when a gateway rejects them — compatibility hardening for proxied/server deployments.
2.1.309: hooks fail-open defects fixed on Windows/PowerShell; a Bash permission check no longer trusts a variable set by a command whose redirect can fail.
Rendering diagram…
Assessment
The releases remain corrective and safety-focused rather than feature-driven. For yoyo, the actionable backlog is narrow: implement real truncation of oversized nested instruction files (#1070), and show the named path alongside the canonical target in the outside-read prompt. The remaining items are already covered or were fixed earlier (#1072, external_tool_failure_note, sub_agent_child_tools).