The AI Reliability
Knowledge Base

A working reference of LLM failure modes
for engineers building reliable AI systems.

Browse the taxonomy

View all 104 modes

Fabrication

Invented facts and citations

01

The model invents facts, citations, or details that have no support in its sources or available evidence.

8 modes

Faithfulness

Distorting sources or self

02

The response misrepresents the input, source material, or the model's own earlier statements in ways that distort their meaning.

6 modes

Freshness

Stale or outdated information

03

The model presents outdated, time-sensitive, or version-specific information as if it were current.

4 modes

Retrieval

Fetching the wrong evidence

04

The system fails to fetch, rank, filter, or apply the right external evidence.

9 modes

Context

Long-context breakdowns

05

The model loses track of information in long inputs, missing, diluting, or overwriting details that matter.

6 modes

Memory

Bad or stale stored state

06

State carried across turns or sessions is missing, corrupted, out of date, or applied where it doesn't belong.

7 modes

Control

Ignoring instructions or formats

07

The system fails to follow instructions, respect constraints, stay in role, produce the required output format, or behave consistently across phrasings, runs, and model versions.

12 modes

Reasoning

Flawed logic and planning

08

The model errs while interpreting goals, weighing constraints, planning steps, or checking its own work.

9 modes

Tools

Misused or mishandled tools

09

The system skips a needed tool, misuses one, invokes it unsafely, or mishandles its results.

9 modes

Agency

Too much or too little initiative

10

The agent miscalibrates initiative, stopping short of completing the task or acting well beyond its scope.

8 modes

Security

Manipulation, leaks, unsafe behavior

11

Adversarial inputs manipulate the system into leaking protected information or behaving unsafely.

9 modes

Alignment

Pleasing or steering over truth

12

The model prioritizes pleasing, persuading, or mirroring the user over truthfulness and safety.

7 modes

Response Integrity

Wrong tone, depth, or fit

13

The final answer misses the mark on task fit, audience, locale, or actionability, even when the underlying content is sound.

10 modes