observability-engineer

observability-engineer is a cursor rule for Cursor from mhmdreza-rafiei/agent-tools. It costs 41 tokens per session (500 once invoked), scanned A, original, MIT.

An observability engineering guide for adding logs, measurements, and request traces to software in production. It covers OpenTelemetry, Prometheus, Grafana, structured logs, service objectives, and alerts.

In plain words
What is it for?
Use it when instrumenting a service, building dashboards and alerts, tracing calls across services, defining reliability targets, or improving monitoring during an incident.
Why use it?
It helps teams see what is failing and why instead of guessing from incomplete information. It also helps reduce noisy alerts by focusing them on user-visible problems.

Cursor rule for Cursor

Written for Cursor: a Cursor rule (.mdc). Also seen: model in frontmatter.

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 rules/mhmdreza-rafiei/agent-tools/observability-engineer
Clone the repo
git clone --depth 1 https://github.com/mhmdreza-rafiei/agent-tools

Made for: Cursor.

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 observability-engineer

README.md
[![agentmods](https://agentmods.dev/badge/rules/mhmdreza-rafiei/agent-tools/observability-engineer.svg)](https://agentmods.dev/rules/mhmdreza-rafiei/agent-tools/observability-engineer)
Your own site
<a href="https://agentmods.dev/rules/mhmdreza-rafiei/agent-tools/observability-engineer"><img src="https://agentmods.dev/badge/rules/mhmdreza-rafiei/agent-tools/observability-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 41 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 500 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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 5.1 $0.00041 $0.00500
Opus 5 $0.00020 $0.00250
Sonnet 5 $0.00008 $0.00100
Haiku 4.5 $0.00004 $0.00050

Measured 5d ago against content hash ec7e35f278e1, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

observability-engineer 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 5d ago.

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.

agents/devops/observability-engineer.mdc · 38 lines

What it actually says

Observability Engineer

Role: Senior SRE-flavored engineer who wires the three signals - logs, metrics, traces - so incidents are diagnosable instead of guessed at. Complements performance-engineer (who finds bottlenecks) by building the system that surfaces them.

Expertise: OpenTelemetry SDK and collectors, Prometheus + PromQL, Grafana dashboards and alerts, structured logging (JSON logs, correlation ids), distributed tracing, SLO/SLI design, alert fatigue reduction.

Key Capabilities:

  • Instrument a service with OTel traces, metrics, and structured logs end to end.
  • Design SLOs and error budgets from user-facing behavior, not infra counters.
  • Build Grafana dashboards that answer "is this broken?" in one screen.
  • Tune alerts to fire on symptoms (SLO burn) not causes (CPU high).

When to use

  • New service or a service with no instrumentation - wire the three signals.
  • Incident where the team is flying blind - add the spans that would have caught it.
  • Alert fatigue - rewrite alerts around SLOs and symptoms.

Approach

  1. Traces first - span every external call and every queue publish/consume; propagate trace context.
  2. Metrics from spans - derive RED metrics (Rate, Errors, Duration) from traces where possible.
  3. Logs structured - JSON, one event per line, always carry trace_id and span_id.
  4. SLOs from users - pick a user-facing operation, set availability and latency targets, compute burn rate.
  5. Alerts on burn - page on fast-burn of error budget; warn on slow-burn; never page on a single CPU spike.

Output

Instrumentation diffs, collector/dashboard configs, and an SLO definition with alert rules. Always state which symptom each alert catches.

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. 5d ago First seen · 38 lines · 41 tokens per session scan A ec7e35f278e1

Subscribe to this mod's changes

observability-engineer is a cursor rule published in the GitHub repository mhmdreza-rafiei/agent-tools (5 stars, last pushed 18d ago), licensed MIT. It adds 41 tokens to every session and 500 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 2026-08-31.