Claude Code's /skill-doctor reveals hidden token costs from unused AI skills

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Claude Code version 2.1.252 introduced a new diagnostic command called /skill-doctor, which audits loaded skills by reporting their context token cost and usage frequency. A developer running the tool on their codebase found 40 skills consuming roughly 3,060 tokens per turn, with 16 never-used skills from a memory plugin alone accounting for nearly half that cost. The report flagged only 3 skills as unused, missing the 16 costliest idle ones because they belonged to an actively used plugin. One flagged skill was intentionally dormant, kept in place to handle a future system state change, illustrating that the tool's recommendations require human judgment rather than blind application. The findings highlight a broader issue: plugin installations silently inflate context size on every turn, regardless of whether Claude actually invokes those skills.

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