Evidence-driven tracing lane that orchestrates competing tracer hypotheses in Claude built-in team mode

Trace Skill Use this skill for ambiguous, causal, evidence heavy questions where the goal is to explain why an observed result happened, not to jump directly into fixing or rewriting code. This is the orchestration layer on top of the built in tracer agent. The goal is to make tracing feel like a reusable OMC operating lane: restate the observation, generate competing explanations, gather evidence in parallel, rank the explanations, and propose the next probe that would collapse uncertainty fastest. Good entry cases Use /oh my claudecode:trace when the problem is: ambiguous causal evidence heavy best answered by exploring competing explanations in parallel Examples: runtime bugs and regressions performance / latency / resource behavior architecture / premortem / postmortem analysis scientific or experimental result tracing config / routing / orchestration behavior explanation “given this output, trace back the likely causes” Core tracing contract Always preserve these distinctions: 1. Observation what was actually observed 2. Hypotheses competing explanations 3. Evidence For what supports each explanation 4. Evidence Against / Gaps what contradicts it or is still missing 5. Current Best Explanation the leading explanation right now 6. Critical Unknown the missing fact keeping the top explanations apart 7. Discriminating Probe the highest value next step to collapse uncertainty Do not collapse into: a generic fix it coding loop a generic debugger summary a raw dump of worker output fake certainty when evidence is incomplete Evidence strength hierarchy Treat evidence as ranked, not flat. From strongest to weakest: 1. Controlled reproductions / direct experiments / uniquely discriminating artifacts 2. Primary source artifacts with tight provenance (trace events, logs, metrics, benchmark outputs, configs, git history, file:line behavior) 3. Multiple independent sources converging on the same explanation 4. Single source code path or behavioral inference 5. Weak circumstantial clues (timing, naming, stack order, resemblance to prior bugs) 6. Intuition / analogy / speculation Explicitly down rank hypotheses that depend mostly on lower tiers when stronger contradictory evidence exists. Strong falsification / disconfirmation rules Every serious /trace run must try to falsify its own favorite explanation. For each top hypothesis: collect evidence for it collect evidence against it state what distinctive prediction it makes state what observation would be hard to reconcile with it identify the cheapest probe that would discriminate it from the next best alternative Down rank a hypothesis when: direct evidence contradicts it it survives only by adding new unverified assumptions it makes no distinctive prediction compared with rivals a stronger alternative explains the same facts with fewer assumptions its support is mostly circumstantial while the rival has stronger evidence tiers Team mode orchestration shape Use Claude built in team mode for /trace . The lead should: 1. Restate the observed result or “why” question precisely 2. Extract the tracing target 3. Generate multiple deliberately different candidate hypotheses 4. Spawn 3 tracer lanes by default in team mode 5. Assign one tracer worker per lane 6. Instruct each tracer worker to gather evidence for and against its lane 7. Run a rebuttal round between the leading hypothesis and the strongest remaining alternative 8. Detect whether the top lanes genuinely differ or actually converge on the same root cause 9. Merge findings into a ranked synthesis with an explicit critical unknown and discriminating probe Important: workers should pursue deliberately different explanations, not the same explanation in parallel. Default hypothesis lanes for v1 Unless the prompt strongly suggests a better partition, use these 3 default lanes: 1. Code path / implementation cause 2. Config / environment / orchestration cause 3. Measurement / artifact / assumption mismatch cause — covers verification method defects, not just system defects. Examples: the verification query reuses a single dimensional key across distinct entities, tenants, streams, or groups; the comparison filter shape does not match the schema grain; or the catalog or column name was assumed portable across runtimes without enumeration. This includes multi entity premise/key assumption mismatches. For lane 3, cross entity discrepancies need a premise audit before escalation: enumerate entity dimensions and check whether a zero row or mismatch result came from applying one key across multiple entities rather than from a system defect; the result may be a verification methodology defect. These defaults are intentionally broad so the first slice works across bug, performance, architecture, and experiment tracing. Mandatory cross check lenses After the initial evidence pass, pressure test the leaders with these lenses when relevant: Systems lens queues, retries, backpressure, feedback loops, upstream/downstream dependencies, boundary failures, coordination effects Premortem lens assume the current best explanation is incomplete or wrong; what failure mode would embarrass the trace later? Science lens controls, confounders, measurement bias, alternative variables, falsifiable predictions These lenses are not filler. Use them when they can surface a missed explanation, hidden dependency, or weak inference. Worker contract Each worker should be a tracer lane owner, not a generic executor. Each worker must: own exactly one hypothesis lane restate its lane hypothesis explicitly gather evidence for the lane gather evidence against the lane rank the evidence strength behind its case call out missing evidence, failed predictions, and remaining uncertainty name the critical unknown for the lane recommend the best lane specific discriminating probe avoid collapsing into implementation unless explicitly told to do so Useful evidence sources include: relevant code, tests, configs, docs, logs, outputs, and benchmark artifacts existing trace artifacts via trace timeline existing aggregate trace evidence via trace summary Recommended worker return structure: 1. Lane 2. Hypothesis 3. Evidence For 4. Evidence Against / Gaps 5. Evidence Strength 6. Critical Unknown 7. Best Discriminating Probe 8. Confidence Leader synthesis contract The final /trace answer should synthesize, not just concatenate. Return: 1. Observed Result 2. Ranked Hypotheses 3. Evidence Summary by Hypothesis 4. Evidence Against / Missing Evidence 5. Rebuttal Round 6. Convergence / Separation Notes 7. Most Likely Explanation 8. Critical Unknown 9. Recommended Discriminating Probe 10. Additional Trace Lanes (optional, only if uncertainty remains high) Preserve a ranked shortlist even if one explanation is currently dominant. Rebuttal round and convergence detection Before closing the trace: let the strongest non leading lane present its best rebuttal to the current leader force the leader to answer the rebuttal with evidence, not assertion if the rebuttal materially weakens the leader, re rank the table if two “different” hypotheses reduce to the same underlying mechanism, merge them and say so explicitly if two hypotheses still imply different next probes, keep them separate even if they sound similar Do not claim convergence just because multiple workers use similar language. Convergence requires either: the same root causal mechanism, or independent evidence streams pointing to the same explanation Explicit down ranking guidance The lead should explicitly say why a hypothesis moved down: contradicted by stronger evidence lacks the observation it predicted requires extra ad hoc assumptions explains fewer facts than the leader lost the rebuttal round converged into a stronger parent explanation This is important because /trace should teach the reader why one explanation outranks another, not just present a final table. Suggested lead prompt skeleton Use a team oriented orchestration prompt along these lines: 1. “Restate the observation exactly.” 2. “Generate 3 deliberately different hypotheses.” 3. “Create one tracer lane per hypothesis using Claude built in team mode.” 4. “For each lane, gather evidence for and against, rank evidence strength, and name the critical unknown plus best discriminating probe.” 5. “Apply systems, premortem, and science lenses to the leaders if useful.” 6. “Run a rebuttal round between the top two explanations.” 7. “Return a ranked explanation table, convergence notes, the critical unknown, and the single best discriminating probe.” Output quality bar Good /trace output is: evidence backed concise but rigorous skeptical of premature certainty explicit about missing evidence practical about the next action explicit about why weaker explanations were down ranked Example final synthesis shape Observed Result [What happened] Ranked Hypotheses Rank Hypothesis Confidence Evidence Strength Why it leads 1 ... High / Medium / Low Strong / Moderate / Weak ... Evidence Summary by Hypothesis Hypothesis 1: ... Hypothesis 2: ... Hypothesis 3: ... Evidence Against / Missing Evidence Hypothesis 1: ... Hypothesis 2: ... Hypothesis 3: ... Rebuttal Round Best rebuttal to leader: ... Why leader held / failed: ... Convergence / Separation Notes ... Most Likely Explanation [Current best explanation] Critical Unknown [Single missing fact keeping uncertainty open] Recommended Discriminating Probe [Single next probe] Additional Trace Lanes [Only if uncertainty remains high]