Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.278 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.269 ·

Agent/task description and reason fields are now sanitized and length-capped

Agent and task description/reason fields are now cleaned up and capped at 1024 characters, and tool-use IDs must match a strict pattern

TierUnder the hoodhow much it should matter to you
Useful1my rating, 1 to 5
Signal1worth watching, 1 to 5
AreaSubagentswhat it touches
KindImprovementsin v2.1.269,
Under the hood

Agent and task description/reason fields are now cleaned up and capped at 1024 characters, and tool-use IDs must match a strict pattern

What

Several internal fields used when spawning a subagent, running a background bash task, or setting a scheduled reminder or loop are now run through a sanitizer before use:

  • description and reason strings have control characters and unusual formatting characters stripped, extra whitespace collapsed, and leading/trailing whitespace trimmed
  • these strings are now truncated to 1024 characters, with an ellipsis added if they were cut off
  • toolUseId fields (identifiers used to track a specific tool call) must now match a strict pattern of letters, numbers, and the characters _, ., :, -, up to 128 characters, instead of being accepted as any string
Why

This prevents malformed, oversized, or oddly-formatted text from leaking into internal descriptions and reasons, and closes off invalid tool-use identifiers from being accepted where a stricter format was always intended.

See this entry in the whole of v2.1.269 →