Red Teaming Your Own Agent
Four weeks in, you have two toolkits. An offensive one, every attack from weeks one to three, and a defensive one, every control from week four. Today you point the first at the second. Red teaming your own agent is the exercise that proves your defenses actually work, finds the gaps you missed, and produces the assessment that the final two days turn into a professional methodology and report.
This is where theory becomes evidence. Anyone can claim their agent is secure. A red team exercise is how you find out, by attacking it with everything you have and recording exactly what held and what did not. It is also the single most valuable thing you can do before shipping an agent, and the service a professional sells.
Why red team your own build
Three reasons this matters more than it sounds.
Defenses fail in ways you cannot predict from the design. You scoped a tool, but did you scope every tool. You added logging, but does it actually capture the chain. You built a dual LLM boundary, but is the channel truly narrow. Design review catches intended gaps. Red teaming catches the ones you did not intend, which are the ones that get exploited.
It converts belief into evidence. Before red teaming, you believe your scoping works. After, you have a table showing this attack landed and reached nothing because of this control. That evidence is what a report needs, what a team trusts, and what separates a real assessment from a vibe.
It is adversarial, so it finds what passive testing misses. Running your own payloads once and seeing them fail proves little, the Day 16 lesson that injection is probabilistic. Red teaming means attacking systematically, adaptively, many times, the way a real attacker would, which surfaces the edge case where a defense you trusted quietly does not hold.
The method: systematic, not random
Red teaming is not poking at the agent hoping something breaks. It is a structured walk through everything you have learned, against your own target. The structure, drawn from the whole series:
Phase 1, map the target. Even though it is your own agent, profile it as if you did not build it. Run your Day 12 enumeration. List every tool, its reach, its identity, every data source and its trust level, every exit. Build the trifecta checklist and the attack surface map. You are producing the attacker’s view of your own system, which is often different from the builder’s view, and that difference is where bugs hide.
Phase 2, enumerate the chains. From the map, list every entry to target to exit chain, the Day 4 and Day 6 method. For each, write the attack you would run. This is your test plan, derived from structure, not guesswork.
Phase 3, attack each chain. Run every attack from weeks one to three that applies: tool poisoning, rug pulls, shadowing, confused deputy, the delivery vectors, the payload families, memory and RAG poisoning, the exfiltration channels. For each, record the outcome, landed and reached the target, landed and reached nothing, or did not land, and crucially, measure as a rate, not a single try, since injection is probabilistic.
Phase 4, verify the defenses. For each defense you built, confirm it actually did its job under attack. Did scoping refuse the cross boundary reach. Did the dual LLM channel hold. Did logging capture a reconstructable chain. A defense that was present but did not fire is a defense that failed, and you only learn which is which by attacking.
Phase 5, record the gaps. Every chain that reached something it should not is a finding against your own agent. Write it up exactly as you would a client finding, because that is what the next two days formalize.
What to attack, the checklist
Walk your own agent through the whole series. For each, attack and record.
- Tool definitions: poisoned descriptions, hidden instructions, cross server influence, rug pull over time. Does your pinning catch it.
- Identity and tokens: confused deputy, can an injection reach beyond the current user via a broad token. Does scoping hold.
- Delivery vectors: every mouth from Day 15, tickets, files, names, errors, metadata, memory. Which reach context.
- Payloads: the framing families from Day 16, measured as success rates against your agent.
- Memory and RAG: plant in one session, fire in another. Does it reach anything.
- Exfiltration: every exit from Day 21, including the sneaky markdown and DNS channels. Does egress constraint hold, does logging see it.
- The full chains: can you get from any entry, through any target, to any exit. This is the real test.
The goal is not to pass. The goal is to find where you do not pass, because every gap you find yourself is a gap an attacker does not get to find for you.
The honest posture: you will find things
A red team exercise that finds nothing is almost always a bad red team exercise, not a perfect agent. If you attacked thoroughly and found no gaps, suspect your attacks, not your defenses. Real systems have gaps. The scoping you forgot on one tool. The exit you did not know was an exit. The logging that misses the cross session case. Finding them is success, not failure.
This is the mindset shift from builder to breaker, applied to your own work. As a builder you want it to work. As a red teamer you want it to break, because every break you cause in the lab is one an attacker cannot cause in production. Hold the breaker’s mindset ruthlessly against your own build, and be glad when it breaks.
Produce the assessment
The output of the exercise is a document, the draft of what Day 29 and 30 formalize. Structure it as:
Scope. What you tested, the agent, its tools, its version, the boundaries of the exercise.
Methodology. How you tested, the systematic walk above, so the result is reproducible and credible.
Findings. Each gap, written as: the chain, the outcome, the impact, the control that should have stopped it and why it did not, and the fix. Ranked by severity.
What held. Equally important, the defenses that worked, with the evidence. This is what gives confidence in the parts you are not changing.
Remediation. The prioritized list of fixes, cheapest-highest-leverage first, which after week four you know is usually scoping.
That document is the deliverable. It is proof of what your agent does under attack, and it is exactly the artifact a security assessment produces.
Reproduce it in the lab
Run the full exercise against your lab agent.
- Profile your own agent as an attacker would, Phase 1. Build the attack surface map fresh, not from memory of building it.
- Enumerate every chain, Phase 2, as your test plan.
- Attack each, Phase 3, measuring outcomes as rates, running the full weeks one to three arsenal.
- Verify each defense actually fired under attack, Phase 4.
- Write the assessment, Phase 5: scope, methodology, findings with severity, what held, remediation.
The exercise to feel: attacking your own build with the breaker’s mindset, you find the gap you were sure was not there. That gap, found by you in the lab, is the whole value of red teaming, and the document you produce is your proof of competence at both halves of the craft.
Detection and defense, where this sits
Red teaming is the validation layer over everything.
- It tests scoping, Day 25, dual LLM, Day 23, flow control, Day 24, and logging, Day 26, under real attack rather than on paper.
- It uses the full offensive series as its method, which is why you learned to attack before you learned to defend.
- It produces the evidence that turns claimed security into demonstrated security, the difference between we think it is safe and here is what happened when we attacked it.
The thesis, brought full circle: you cannot know your defenses work until you attack them, so you red team your own agent with everything you have, find the gaps yourself, and fix them before an adversary finds them for you. Offense and defense are one skill, and red teaming is where they meet.
Homework for Day 28
- Profile your lab agent fresh as an attacker, building the full attack surface map.
- Enumerate every entry to target to exit chain as your test plan.
- Run the complete weeks one to three arsenal against it, recording each outcome as a rate.
- Verify every week four defense actually fired under attack, and note any that were present but did not hold.
- Write the full assessment document: scope, methodology, ranked findings, what held, remediation.
Point 5 is the capstone. A complete, honest assessment of your own agent, produced by attacking it with everything you have learned, is the single artifact that proves you can do this work, and it is the raw material the final two days turn into a professional methodology and report.
Day 29 formalizes the method into a repeatable agent pentest methodology, the structured process you run on any agent, so the thorough exercise you just did becomes a standard procedure rather than a one off.
