Diagnose why an agent harness misbehaved by reading the local flight-recorder ledger (.vigiles/runs.jsonl) — which skills fired or got hijacked, which hooks blocked or wrongly allowed, which subagent tool-contract violations happened, and how a skill's trigger rate moved. Use when asked why a skill

Diagnose harness misbehavior from the flight recorder — the local, append only ledger at .vigiles/runs.jsonl that vigiles writes as your harness runs. It records what actually happened, so you debug from evidence instead of guessing. What's in the ledger One JSON record per line, each with a kind : hook — a compiled hook gate decision: {event, decision: allow deny ask, mode: enforce observe, rule, cmd, reason} . agent — a subagent tool contract decision: {name, tool, allowed, reason} (a false = the agent went outside its lane). skill — a skill activation: {name, fired} . eval — a measured metric: {name, metric, value} (e.g. trigger rate recall/precision). capability diff — a blast radius change: {pr, added, removed, widened} . Instructions Step 1: Read the ledger Read .vigiles/runs.jsonl (JSONL — one record per line; tolerate a torn last line). If it's absent or empty, say so — there's nothing recorded yet; suggest running the harness (or vigiles audit ) first. Do NOT fabricate records. Step 2: Answer the specific question, evidence first Match the user's question to the ledger: "Why did skill X stop firing / why does the wrong one run?" — count skill fires by name over time. If X's fire rate dropped, look for a sibling that fired on the same kinds of prompts (a selection collision ) and check their descriptions for overlap. Recommend differentiating or merging the descriptions. "Why didn't my hook block that?" — find hook records for the event. A decision: allow on something that should be denied, or mode: observe (shadow, never blocks), or the absence of any record, tells you which. Recommend flipping observe → enforce or fixing the gate logic. "Did a subagent misbehave?" — list agent records with allowed: false : the agent reached for a tool outside its declared contract. Point at the contract to tighten or widen. "Is it getting worse?" — compare eval metric values (recall/precision) across runs; a downward trend is drift (often after a harness/model upgrade). Step 3: Recommend a fix, tied to the evidence Prefer promoting an ignored but decidable rule from prose to a deterministic gate : a repeated agent violation or a rule the agent keeps breaking → a compiled hook or a tighter tool contract (the strengthen skill can help). A description collision → differentiate the skill descriptions. Always cite the specific records you based the diagnosis on. Step 4: Offer the next step If the fix is a spec change, hand off to edit spec . If it's promoting guidance to a linter rule, hand off to strengthen . If a behavioral claim needs measuring (does the skill fire now?), hand off to test harness ( measureTriggerRate ).

debug-my-harness