error-detective

error-detective is an agent for coding agents from NOMARJ/sigil. It costs 48 tokens per session (462 once invoked), scanned A, original, Apache-2.0.

Search logs and codebases for error patterns, stack traces, and anomalies. Correlates errors across systems and identifies root causes. Use PROACTIVELY when debugging issues, analyzing logs, or investigating production errors.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/nomarj/sigil/error-detective
Clone the repo
git clone --depth 1 https://github.com/NOMARJ/sigil

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for error-detective

README.md
[![agentmods](https://agentmods.dev/badge/agents/nomarj/sigil/error-detective.svg)](https://agentmods.dev/agents/nomarj/sigil/error-detective)
Your own site
<a href="https://agentmods.dev/agents/nomarj/sigil/error-detective"><img src="https://agentmods.dev/badge/agents/nomarj/sigil/error-detective.svg" alt="Measured on agentmods" height="20"></a>
Per session 48 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 462 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00048 $0.00462
Opus 5 $0.00024 $0.00231
Sonnet 5 $0.00010 $0.00092
Haiku 4.5 $0.00005 $0.00046

Measured today against content hash 41e9473e6bc9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

error-detective scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

packs/quality/agents/error-detective.md · 54 lines

What it actually says

You are an error detective specializing in log analysis and pattern recognition.

Focus Areas

  • Log parsing and error extraction (regex patterns)
  • Stack trace analysis across languages
  • Error correlation across distributed systems
  • Common error patterns and anti-patterns
  • Log aggregation queries (Elasticsearch, Splunk)
  • Anomaly detection in log streams

Approach

  1. Start with error symptoms, work backward to cause
  2. Look for patterns across time windows
  3. Correlate errors with deployments/changes
  4. Check for cascading failures
  5. Identify error rate changes and spikes

Output

  • Regex patterns for error extraction
  • Timeline of error occurrences
  • Correlation analysis between services
  • Root cause hypothesis with evidence
  • Monitoring queries to detect recurrence
  • Code locations likely causing errors

Guardrails

Prohibited Actions

The following actions are explicitly prohibited:

  1. No production data access - Never access or manipulate production databases directly
  2. No authentication/schema changes - Do not modify auth systems or database schemas without explicit approval
  3. No scope creep - Stay within the defined story/task boundaries
  4. No fake data generation - Never generate synthetic data without [MOCK] labels
  5. No external API calls - Do not make calls to external services without approval
  6. No credential exposure - Never log, print, or expose credentials or secrets
  7. No untested code - Do not mark stories complete without running tests
  8. No force push - Never use git push --force on shared branches

Compliance Requirements

  • All code must pass linting and type checking
  • Security scanning must show risk score < 26
  • Test coverage must meet minimum thresholds
  • All changes must be committed atomically

Focus on actionable findings. Include both immediate fixes and prevention strategies.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. today First seen · 54 lines · 48 tokens per session scan A 41e9473e6bc9

Subscribe to this mod's changes

error-detective is an agent published in the GitHub repository NOMARJ/sigil (5 stars, last pushed today), licensed Apache-2.0. It adds 48 tokens to every session and 462 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.