Tutorials · Developers
Claude Code, MCP, hooks and the things that break at the edges. We run them, break them, and report the numbers.
We denied reads of one file and calls to curl, then tried eight ways around it. Six were blocked, including cat, sed and a chained command. The two that were not still stopped and asked.
We probed a single MCP server installed with one line of npx config. It exposes 372 tools and 335,954 bytes of JSON schema, roughly 42 percent of a 200K context window.
A three-token headless prompt sent 44,137 tokens of preamble and cost 31 cents. The identical command four seconds later cost 2.2 cents.
A PreToolUse hook that blocks rm -rf took ten minutes to write and caught 2 of 6 ways to delete a directory. Worse, it failed open: broken, it exited 0 and let the delete through.
An audit of 77 Claude Code rule files found 22 loading on every session, and 10 of those were Chinese translations of the other 10. That is 4,265 tokens of duplicate instruction per session.
Claude Code budgets its skill listing at 1 percent of the context window. We counted 228 skills across four scopes totalling 50,606 characters, 25 times over budget on a 200K model.
Install takes two minutes. The part worth learning is skills, and the guides skip it. Six of them now produce this site: 5 articles, 6,883 words, and 2 mistakes that cost us an afternoon.
A blocked write returns 204 No Content, which looks exactly like success. We ran the full verification against a live project and found 3 things the dashboard will not tell you.