Skills as invocation contracts, not code: how I keep review authority over agent work

When a skill is code, you review code. When a skill is a markdown contract, you review the contract — and the implementation gets re-typed by an agent under it. One scales to dozens of agents operating on the same surface. The other collapses the moment the implementation needs to be re-read by a human. This is the pattern I run in claude-code-mcp-qa-automation . Sixteen skills live as pure markdown files. The Python implementation underneath can be swapped — rewritten, refactored, replaced — wi