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 v2.1.221 Home All releases olderv2.1.220 v2.1.222newer

Agent SDK rejects skill names containing parentheses, commas or control characters

You'll notice
Useful2 Signal0
Skills

Skill names with parentheses, commas or control characters now fail validation immediately instead of silently breaking.

What

Skill-name validation gained a rule blocking (, ), , and C0/C1 control characters, so those names now fail up front rather than producing a name that cannot match a directory.

Details
  • Sits on top of the existing unpaired-surrogate, whitespace and wildcard rules.
  • The error explains that skill names must match the skill's directory name.
  • Applies to everyone on this build.
Evidence

parentheses, commas, and control characters are not allowed in skill names

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

See this entry in the whole of v2.1.221 →