Test: Claude Code drops skill descriptions when listing overflows

An experiment with Claude Code 2.1.289 and Opus 5.5 found that with 160 skills using 1,000-character descriptions, the listing was capped at 30,000 characters, only 20 skills kept their descriptions, and the model invoked 0 of 3 name-only skills versus 7 of 7 with descriptions.

• Skill listing budget is 1% of the model's context window, or 30,000 characters for Opus 5.5
• Of 160 skills only 20 kept descriptions: 22 of 40 and 21 of 80 in smaller sets
• The model invoked 0 of 3 name-only skills and 7 of 7 skills with descriptions
• Each description is capped at 1,536 characters, configurable via skillListingMaxDescChars