Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.227 Home All releases olderv2.1.226 v2.1.228newer
Claude Code v2.1.227

Prompt section discouraging over-delegation to subagents

Not switched on
Useful3 Signal4
Subagents Notable not in their notes

Claude can be told to stop over-spawning subagents for small tasks, but that guidance is absent by default.

An anti-over-delegation prompt section only appears when CLAUDE_CODE_THISTLE_GREBE or its flag selects counter_steer.

Feature flag
tengu_thistle_grebe Not enough to say

Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.

This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.227: not a boolean we can read

These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.

Read once, for one account on one subscription tier, against v2.1.227. It isn't a statement about your account. What a flag value here can and cannot tell you

CLAUDE_CODE_THISTLE_GREBE
What

A "## Delegating to subagents" section tells Claude to handle small bounded sub-tasks inline, not to fan several subagents out on one small task, not to spawn one to double-check work it can verify itself, and to keep spawn counts low. It is only injected when the subagent steer resolves to "counter_steer". The steer is read from CLAUDE_CODE_THISTLE_GREBE, client data, the tengu_thistle_grebe flag, or a per-model floor, and defaults to "default", so the section is absent unless configured.

Details
  • Applying any non-default steer emits a tengu_subagent_steer_applied event.
Evidence

Subagents multiply cost and time: each one re-establishes context, re-explores, and reports back

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.227 →