Continuous AI Evaluations for Better Production Agents

A continual learning loop across the agentic lifecycle.
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Close the Loop from Testing to Production

Without a continual learning loop, teams have no systematic way to catch hallucinated answers, broken tool calls, or off-rails reasoning chains in AI agents before they reach users. When failures surface, root causes are buried in scattered logs. And fixes can't be validated without waiting for the next wave of production traffic.

Evaluate before shipping, observe after shipping, and feed what you learn directly back into the next iteration so every cycle produces a better agent.

How many tokens are you burning?
Find out what the Evaluation Trust Tax is really costing you, the per-trace API cost charged on every evaluation.
Calculate your evaluations’ TCO
Fiddler AI evaluator selection screen showing two options: a Custom Judge configuration for LLM-as-a-Judge with a three-step setup flow, and a Predefined Evaluator panel with ten pre-configured options including Topic Classification, Embedding, Token Count, Answer Relevance, Coherence, Conciseness, Context Relevance, RAG Faithfulness, PII Detection, Sentiment Analysis, FTL Prompt Safety, and FTL Response Faithfulness.

Evaluate Before You Deploy

  • Choose out-of-the-box or custom metrics using Fiddler Centor Models, or bring your own judge (BYOJ), for use cases from low-latency to complex reasoning.
  • Build golden and challenger datasets with auto-mapping, directly in Fiddler.
  • Compare prompts, models, and configurations side by side to see which performs best.
Watch how tests and experiments work

Evaluate Every Decision Agents Make In Production

  • Surface the worst behaving agent sessions by filtering, sorting, and searching spans in Trace Explorer.
  • Track aggregate evaluation scores across your agents to monitor quality trends and surface regressions as they emerge.
  • Catch hallucinations, jailbreaks, roleplaying, and harmful content in real time.
Learn more about agentic observability
Fiddler AI PII/PHI Detection chart showing daily flagged spans over 30 days from April 16 to May 15, 2026, for the DemoAgenticChatbot application. Orange bars represent daily volume with a blue trend line overlaid. A Spans table below shows individual trace records with PII_Detection_Input values marked as true, including input snippets referencing model API integration.
Agentic trace timeline showing a session with span details, bar graph of session and tool activities over time, and metadata including span group ChatOpenAI, span type LLM, start and end times, duration, system instructions, user input, output, and context on the right panel.

Find Exactly Where and Why Agents Fail

  • Drill into the full decision chain to diagnose failures across retrieval, generation, query understanding, tool calls, and agent handoffs.
  • Annotate traces with domain expertise by flagging outputs, labeling root causes, and adding commentary.
See how root cause analysis works

Close the Loop: Turn Insights into Better Agents

  • Feed production scores and annotations into testing and development to build a golden dataset grounded in real behavior.
  • Integrate with CI/CD and regression testing using regression metadata, so improvements are measurable in your existing workflow.
  • Deliver evaluation results as audit evidence for governance and compliance.
Learn how to improve agents
Fiddler AI Experiments view for a completed LLM Q&A evaluation run showing lowest-scoring rows flagged in red, including prompts such as hiding transactions from authorities, ignoring previous instructions, and an overdraft fee question. A results table below shows input, output, and expected output columns alongside answer_relevance and coherence scores, all rated 0.00 for the displayed rows.

Frequently Asked Questions About Evaluations

How do you evaluate AI agents before production?

AI agent evaluation in pre-production involves running agents against curated test datasets and scoring outputs for quality, safety, and compliance. Teams define the metrics that matter for their use case (hallucination, faithfulness, PII, toxicity, jailbreak vulnerability) and test against them before deployment. Fiddler supports experiments where you compare different prompts, models, and configurations side by side against the same test data to find the highest-performing setup before it reaches production.

How do you approach agentic AI evaluation?

Agentic pipelines involve multiple steps, tool calls, agent handoffs, and reasoning chains, so your LLM evaluation pipeline needs to cover more than just the final output. Effective evaluation scores behavior at every level of the agentic hierarchy, from the application down to individual spans, so you can trace a bad outcome back to the specific step that caused it. Fiddler evaluates across the full hierarchy (application, session, agent, trace, span) with the same metrics in testing and production.

What metrics should you use to evaluate AI agents?

Key metrics for AI agent evaluation include hallucination and faithfulness, safety (jailbreak, toxicity, harassment, harmful content), PII/PHI detection, sentiment, profanity, and language detection. Domain-specific KPIs like accuracy, relevance, and compliance metrics are also important depending on the use case. Fiddler supports 80+ out-of-the-box metrics across these categories, plus the ability to define custom evaluators for requirements that off-the-shelf metrics don't cover.

What's the difference between pre-production and production evaluation?

Pre-production evaluation tests agent behavior against curated datasets before deployment. Production evaluation scores live traffic to catch drift, new failure modes, and emerging risks. Most tools cover one or the other. Fiddler runs the same Centor Models in both, so what you measured before launch is exactly what you're monitoring after. Production findings feed back into pre-production test suites.

What is a continual learning loop for AI agents?

A continual learning loop is a process where production evaluation findings feed directly back into pre-production testing, so each iteration of an AI agent improves based on real-world failures rather than synthetic benchmarks. The loop has four steps: evaluate before deployment, observe every decision in production, debug and annotate failures, and feed those annotated traces back into your evaluation datasets. Without this loop, teams patch agents blindly and can't validate whether fixes actually worked.

Why does 100% trace coverage matter for AI evaluation?

When evaluation costs scale per trace, teams sample to control spend, which means a portion of production traffic goes unscored for hallucinations, safety incidents, PII exposure, and policy violations. Fiddler Centor evaluates 100% of traces at a fixed cost, so there's no trade-off between coverage and budget.