claude-api skill description truncated in Claude Code listings

[azarovalex]

The claude-api skill's description field in frontmatter exceeds 250 characters, which causes Claude Code to truncate it in the skill listing.

What Claude Code sees in context:

claude-api: Build apps with the Claude API or Anthropic SDK.
TRIGGER when: code imports `anthropic`/`@anthropic-ai/sdk`/`claude_agent_sdk`, or user asks to use Claude API, Anthropic SDKs, or Agent SDK.
DO NOT TRIGGER when: code imports `openai`/other AI SDK, ge…

The DO NOT TRIGGER when conditions are cut off, which means Claude may incorrectly invoke this skill when working with non-Anthropic AI SDKs.

Per the Claude Code docs on skills, descriptions longer than 250 characters are truncated in skill listings to reduce context usage. The fix would be to shorten the description to under 250 chars, front-loading the key use case and keeping the exclusion conditions concise.

[azarovalex]

I believe this problem also applies to some other native skills like /loop and /update-config

[ChristopheChirat]

Adding a current, stricter data point on this skill's description length.

Since this issue was filed, the claude-api description was rewritten and is now 1068 characters (the YAML-parsed value of skills/claude-api/SKILL.md on main). Beyond the 250-char listing truncation described here, it now also crosses a hard 1024-character limit, with a more severe consequence in GitHub Copilot CLI (observed v1.0.61–1.0.62):

The following skills failed to load:
✗ ...\anthropic-agent-skills\document-skills\skills\claude-api\SKILL.md: Skill ...

i.e. the skill is rejected entirely and does not load — not merely truncated. Copilot CLI ships a native validator (runtime.node) that enforces a max description of 1024 chars ("description ... exceeds maximum"), and the Agent Skills standard documents the same 1024 ceiling.

Repro (provider-agnostic):

import yaml
d = open("skills/claude-api/SKILL.md", encoding="utf-8").read()
desc = yaml.safe_load(d.split("---", 2)[1])["description"]
print(len(desc))  # -> 1068  (44 over the 1024 limit)

Suggested fix: shorten the description below 1024 (ideally < 250 as suggested above, to also avoid the Claude Code listing truncation), while keeping the TRIGGER/SKIP exclusion conditions intact — those are what prevent mis-invocation on non-Anthropic SDKs.

For reference, a 973-char rewrite that preserves the full trigger/skip logic loads cleanly in Copilot CLI. Happy to open a PR if that would help.