Cole-Medin

Cole Medin runs through 11 small tweaks that make any coding agent — Claude Code, Codex, whatever — noticeably more reliable, without scrapping your workflow. The through-line: agents are prediction machines, not deterministic programs, so reliability comes from shrinking their decision space and moving guarantees into deterministic mechanisms. ~17 minutes. Rules and context 1. Write for the agent, not the human. Humans interpret high-level docs in context; agents make assumptions. Be blunt — file paths, numbers, exact commands. 2. Your instruction files rot. “Rule drift”: 1 in 4 repos have stale AI rules referencing deleted files or replaced databases. Audit them against the codebase. 5. Less context is more. Too many rules hurts as models improve. Keep global rules under ~200–300 lines; drop generic advice and move the rest to task-specific context files. Conversation hygiene 3. /compact loses ~90% of detail. Compacting a bloated conversation breeds hallucination. Give smaller work chunks, or write your own handoff doc and start fresh. 7. Don’t escalate mid-task. A bigger model can’t rescue a tainted conversation — mistakes compound within a session. Write a handoff doc and burn it. 10. Over-revision degrades quality. 85% of the time an earlier iteration was better. The model “fixes” things just to appease you. Determinism over frameworks 4. Load-bearing rules → hooks. Rules are probabilistic (the agent will “forget” to run tests); hooks are deterministic — fire on an event and route failures back. 6. Subagents eat your rate limit. Parallel fanouts cost more than you think — 39% of his weekly usage came from 4+ parallel sessions. 8. You don’t need coordinators. Team-lead frameworks and agent mailboxes are unreliable. A plain delegator agent gets most of the scale with far more reliability. Validation 9. Never let the writer approve the work. The writer carries its own bias. Review in a fresh conversation with a handoff doc — no assumptions carried over. 11. Validation is a system, not a step. Plan the full harness — test conventions, tools, edge cases — before writing any code, not as an afterthought. “Your number one job when you’re planning any work with your coding agent is to reduce the number of assumptions that it’s making.” — Cole Medin ...