Agents
Software that loops — think, act, observe — until the job is done.
An agent is the difference between a tool that drafts your refund email and one that actually issues the refund, updates the CRM, and tells the customer. That shifts the unit of work from a message to an outcome, which is where the labour cost actually sits. It also shifts the risk: a chatbot that is wrong wastes a minute, an agent that is wrong moves money.
You need this when
- Multi-step work across 3+ systems that a human does by tabbing between tabs
- High volume with a checkable definition of done (ticket resolved, PR opened)
- Reversible actions where a wrong run costs minutes, not a lawsuit
You can skip it when
- One-shot writing or summarising — that is a prompt, not an agent
- Fixed deterministic rules — use a script or n8n workflow, it never hallucinates
- Irreversible money or mass-send actions — keep a human approval gate instead
The long version
What it is — in one coffee-break
An agent is a loop. The model thinks (picks a next step), acts (calls a tool, writes a file, hits your CRM), then observes what came back and decides again. Repeat until the goal is met or the budget runs out. That loop is the entire difference between a chatbot, which answers and stops, and an agent, which keeps going until the refund is issued or the pull request is open.
Three things separate a real agent from a demo: autonomy (how many steps it takes before it needs you), reliability (how often those steps end in the right outcome), and integration depth (whether it can actually touch your systems or only talk about them). A vendor can be strong on one and useless on the other two. Gartner counted roughly 130 genuinely agentic vendors out of thousands claiming the label, and named the rest “agent washing”.
When you actually need it (and when you don't)
You need agents when the work is multi-step, repetitive, high-volume and has a checkable definition of done: refund a customer within policy, triage 400 inbound tickets, chase one document across four systems, reproduce a bug and open a fix. The tell is that a human does it today by tabbing between five tools for twenty minutes.
You do not need agents for one-shot generation — write this email is a prompt, not an agent. You do not need them for deterministic work with fixed rules; a script or an n8n workflow is cheaper and never hallucinates. And you should not point them at irreversible actions with no undo: wire transfers, bulk deletion, sending to a full mailing list. Gartner expects over 40% of agentic projects to be scrapped by the end of 2027, mostly for escalating cost, unclear value and missing risk controls. A large share of those are teams who pointed an agent at a problem a rules engine had already solved.
How to recognize good vs bad implementations
Good implementations are boring in the demo and impressive in the logs. Every run is traceable step by step, failures halt instead of improvising, permissions are scoped per tool, and there is an explicit approval gate on anything expensive. Bad ones show you a flawless three-minute happy path and change the subject when you ask about run number 4,000.
Make the vendor answer three questions live: “Show me a run that failed — what did the agent do next, and where is that written down?” “How many tool calls deep does it go before a human has to step in, and what is the success rate at that depth?” “Which actions can it take without asking, and how do I reverse one after the fact?” A vendor who can only answer the first is selling a chatbot with ambition.
Calibrate with real numbers rather than the pitch. On TheAgentCompany, a benchmark of ordinary office work, the most competitive agent completed 30% of tasks autonomously. METR measures a 50%-success time horizon of roughly 320 minutes — about five hours of software work — for the strongest model it has tested, with that horizon doubling every three to four months. Long, open-ended tasks still fail. Short, scoped, well-instrumented ones increasingly do not.
What this costs
Three pricing shapes. Outcome-based: Sierra bills per resolved conversation rather than per seat, so unresolved chats cost nothing — honest, but your bill scales with volume forever. Consumption-based: Devin starts at $20 and burns $2.25 per ACU, where one ACU is about fifteen minutes of agent work; the old flat plan was $500 a month. Seat-based platforms: Glean contracts cluster around a median near $99,000 a year in Vendr's buyer data, ranging from about $30,000 to $209,000.
The free-and-on-premise route is real and it is what most readers here should try first. n8n's self-hosted Community Edition is free (their managed cloud starts at €20/month), and LangGraph, CrewAI and the major vendor agent SDKs are open source. Your hard cost becomes a VPS at €10–40 a month plus model tokens — realistically €50–300 a month for a small-business workload, or close to zero if you run an open-weight model on a GPU you already own. You pay instead in engineering time: the loop itself is a weekend, the evaluation harness, retries, permissions and audit log are the six weeks.
Where to see it scored
We audited 62 tools and scored 56 of them on Ag. Top of the table: Sierra (9.5) and Claude / Anthropic (9.5), followed by Windsurf, Devin Desktop (9) and Glean (9). Bottom of the table: Kling AI (3) and Cognism (3) — both competent products that simply do not run autonomous loops, whatever their marketing pages imply.
Flashcards
Check yourself
1. Which of these is genuinely an agent?
2. Gartner predicts how many agentic AI projects will be canceled by end of 2027?
3. On TheAgentCompany benchmark, the best agent completed what share of tasks autonomously?
4. Which demo question best exposes a weak agent?
5. Cheapest credible way to start with agents on-premise?
Cheat sheet
- Agent = think-act-observe loop; chatbot answers once and stops
- Score three axes: autonomy, reliability, integration depth
- Best agent finished only 30% of office tasks in TheAgentCompany benchmark
- METR: ~5h 50%-success time horizon, doubling every 3-4 months
- Gartner: 40%+ of agentic projects scrapped by end-2027; 130 real vendors
- Self-host free: n8n Community + open SDKs, ~EUR 10-40/mo VPS plus tokens
Who actually does this well
| Best on this element | Score | Why it scored that |
|---|---|---|
| Claude / Anthropic | 9.5 | Claude Code is the category-defining agentic product (>$2.5B run-rate by 02/2026) and the same harness ships as Agent SDK and Managed Agents with computer use — the strongest agent |
| Sierra | 9.5 | Agentic think-act-observe loops are the entire product; agents now act proactively (renewal flags, next-best-action) rather than just responding. |
| Cursor | 9 | Agent-first product: Plan Mode, Checkpoints, Background/Cloud Agents in sandboxes, Automations and BugBot PR review make multi-step autonomous work the default workflow, not a demo |
| Decagon | 9 | Autonomous, multi-step, cross-channel resolution with real side effects — 70-90%+ deflection across named case studies (Chime 70%, Duolingo 80%, Substack 90%+) — docked slightly si |
| Gemini / Google | 9 | Antigravity, the 24/7 Gemini Spark agent, Deep Research and the managed Agent Engine runtime (sessions and memory GA) make a deep, fast-moving agent stack — parts still gated US-on |
| Genspark | 9 | Session-based Super Agent plus a persistent "AI employee" (Genspark Claw) that runs 24/7 on a dedicated cloud computer or locally, connects to WhatsApp/Slack/Teams/Telegram, and re |
| Glean | 9 | No-code workflow agents, autonomous goal-directed agents and a headless git-based builder; Zillow reports 3,400+ agents built, Ericsson 2,700+. |
| Windsurf (Devin Desktop) | 9 | The most agent-centric IDE shipping: Devin Local (Rust rewrite with subagents, claimed ~30% more token-efficient) plus Devin Cloud agents, parallel sessions on git worktrees, and a |
And the other end of the same column:
| Weakest | Score | Why it scored that |
|---|---|---|
| Ideogram | 3.5 | No native agent product; the MCP catalog lets an outside agent chain Ideogram's tools (bulk generation, catalog cleanup, dataset training) in one conversation, but Ideogram ships n |
| Meta Llama ecosystem | 3.5 | No first-party agent runtime remains — the Llama API (with its playgrounds and SDK) was retired on 06/07/2026 and agentic scaffolding around raw weights is fully DIY. |
| Cognism | 3 | Marketing language calls these 'AI agents for GTM', but the shipped behaviour is insight-surfacing on a profile view, not a multi-step autonomous loop working toward a goal. |
| Kling AI | 3 | Multi-shot mode can auto-plan cuts from a single brief, a thin agentic-adjacent feature, but there is no autonomous think-act-observe agent product. |
Scored on 56 of 62 audited tools. Every score links to the full audit and its reasoning.