Skill descriptions consume too much context budget per session

Installing the plugin adds 13 aws-core:* skills to the listing that is injected into every session's context. Even without invoking any skill, the description text for these skills costs ~1,600 tokens per session — roughly 73% of Claude Code's default 1% skill listing budget.

This causes the harness to emit a truncation warning and drop skill descriptions silently:

Skill listing will be truncated
11 descriptions dropped (full descriptions kept for most-used skills)
run /skills to disable some, or raise skillListingBudgetFraction in settings.json

Measured description sizes (chars/4 approximation):

The descriptions are long because they double as trigger conditions ("ALSO USE for...", "Use this skill whenever..."), which is understandable — but it means installing this plugin has a persistent per-session cost even when doing nothing AWS-related.

Possible mitigations (in order of preference):

1. Trim descriptions — separate the trigger heuristics from the user-facing description; only the short description needs to be in the listing
2. Opt-in skills — let users enable only the aws-core:* skills they actually use, rather than registering all 13 on install
3. Lazy listing — only surface skills in the listing when the working directory contains AWS-related files (e.g., amplify/, cdk.json, template.yaml, *.tf)

Install the plugin and reproduce the skill-listing truncation warning, then inspect how the 13 aws-core skills and their descriptions are registered. Compare the proposed trimming, opt-in, and lazy-listing approaches with maintainers; done means AWS skill descriptions no longer consume excessive per-session context or trigger silent truncation.