All Descriptors

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Deterministic evals

Programmatic and heuristics-based evaluations.

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Pattern match

Check for general pattern matching.

Name	Description	Parameters
ExactMatch()	Checks if the column contents matches between two provided columns. Returns True/False for every input. Example: ExactMatch(columns=["answer", "target"])	Required: columns Optional: alias
RegExp()	Matches the text against a set regular expression. Returns True/False for every input. Example: RegExp(reg_exp=r"^I")	Required: reg_exp Optional: alias
BeginsWith()	Checks if the text starts with a given combination. Returns True/False for every input. Example: BeginsWith(prefix="How")	Required: prefix Optional: alias case_sensitive = True or False
EndsWith()	Checks if the text ends with a given combination. Returns True/False for every input. Example: EndsWith(suffix="Thank you.")	Required: suffix Optional: alias case_sensitive = True or False

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Content checks

Verify presence of specific words, items or components.

Name	Description	Parameters
Contains()	Checks if the text contains any or all specified items (e.g., competitor names). Returns True/False for every input. Example: Contains(items=["chatgpt"])	Required: items: List[str] Optional: alias mode = any or all case_sensitive = True or False
DoesNotContain()	Checks if the text does not contain the specified items (e.g., forbidden expressions). Returns True/False for every input. Example: DoesNotContain(items=["as a large language model"])	Required: items: List[str] Optional: alias mode = all case_sensitive = True or False
IncludesWords()	Checks if the text includes any or all specified words. Considers only vocabulary words. Returns True/False for every input. Example: IncludesWords(words_list=['booking', 'hotel', 'flight'])	Required: words_list: List[str] Optional: alias mode = any or all lemmatize = True or False
ExcludesWords()	Checks if the texts excludes all specified words (e.g. profanity lists). Considers only vocabulary words. Returns True/False for every input. Example: ExcludesWords(words_list=['buy', 'sell', 'bet'])	Required: words_list: List[str] Optional: alias mode = all lemmatize = True or False
ItemMatch()	Checks if the text contains any or all specified items. The item list is specific to each row and provided in a separate column. Returns True/False for each row. Example: ItemMatch(["Answer", "Expected_items"])	Required: columns Optional: alias mode = all or any case_sensitive = True or False
ItemNoMatch()	Checks if the text excludes all specified items. The item list is specific to each row and provided in a separate column. Returns True/False for each row. Example: ItemMatch(["Answer", "Forbidden_items"])	Required: columns Optional: alias mode = all case_sensitive = True or False
WordMatch()	Checks if the text includes any or all specified words. Word list is specific to each row and provided in a separate column. Considers only vocabulary words. Returns True/False for every input. Example: WordMatch(["Answer", "Expected_words"]	Required: columns Optional: alias mode = any or all lemmatize = True or False
WordNoMatch()	Checks if the text excludes all specified words. Word list is specific to each row and provided in a separate column. Considers only vocabulary words. Returns True/False for every input. Example: WordNoMatch(["Answer", "Forbidden_words"]	Required: columnsstr Optional: alias mode = all lemmatize = True or False
ContainsLink()	Checks if the column contains at least one valid URL. Returns True/False for each row.	Optional: alias

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Syntax validation

Validate structured data formats or code syntax.

Name	Description	Parameters
IsValidJSON()	Checks if the column contains a valid JSON. Returns True/False for every input.	Optional: alias
JSONSchemaMatch()	Checks if the column contains a valid JSON object matching the expected schema: all keys are present and values are not None. Exact match mode checks no extra keys are present. Optional type validation for each key. Returns True/False for each input. Example: JSONSchemaMatch(expected_schema={"name": str, "age": int}, exact_match=False, validate_types=True)	Required: expected_schema: Dict[str, type] Optional: exact_match = True or False validate_types = True or False
JSONMatch()	Checks if the column contains a valid JSON object matching a JSON provided in a reference column. Matches key-value pairs irrespective of order. Whitespace outside of the actual values (e.g., spaces or newlines) is ignored. Returns True/False for every input. Example: JSONMatch(first_column="Json1", second_column="Json2"),	Required: first_column second_column Optional: alias
IsValidPython()	Checks if the column contains valid Python code without syntax errors. Returns True/False for every input.	Optional: alias
IsValidSQL()	Checks if the column contains a valid SQL query without executing the query. Returns True/False for every input.	Optional: alias

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Text stats

Descriptive text statistics.

Name	Descriptor	Parameters
TextLength()	Measures the length of the text in symbols. Returns an absolute number.	Optional: alias
OOVWordsPercentage()	Calculates the percentage of out-of-vocabulary words based on imported NLTK vocabulary. Returns a score on a scale: 0 to 100.	Optional: alias ignore_words: Tuple = ()
NonLetterCharacterPercentage()	Calculates the percentage of non-letter characters. Returns a score on a scale: 0 to 100.	Optional: alias
SentenceCount()	Counts the number of sentences in the text. Returns an absolute number.	Optional: alias
WordCount()	Counts the number of words in the text. Returns an absolute number.	Optional: alias

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Custom

Implement your own programmatic checks.

Name	Descriptor	Parameters
CustomDescriptor()	Implements a custom check for specific column(s) as a Python function. Use it to run your own programmatic checks. Returns score and/or label as specified. Can accept and return multiple columns.	Optional: alias func: callable See how to add a custom descriptor.
CustomColumnsDescriptor()	Implements a custom check as a Python function that can be applied to any column in the dataset. Use it to run your own programmatic checks. Returns score and/or label as specified. Accepts and returns a single column.	Optional: alias func: callable See how to add a custom descriptor.

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LLM-based evals

Using an external LLMs with an evaluation prompt. You can specify the LLM to use as an evaluator.

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Custom

LLM judge templates.

Name	Descriptor	Parameters
LLMEval()	Scores the text using user-defined criteria. You must specify provider, model and use prompt template to formulate the criteria. Returns score and/or label as specified.	Optional: alias template provider model additional_columns: dict See custom LLM judge parameters.

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RAG

RAG-specific evals for retrieval and generation. (Tutorial).

Name	Descriptor	Parameters
ContextQualityLLMEval()	Evaluates if the context provides sufficient information to answer the question. Returns a label (VALID or INVALID) or a score. Run over the “context” column and pass the question column as a parameter. Example: ContextQualityLLMEval("Context", question="Question")	Required: question Optional: alias provider model See LLM judge parameters.
ContextRelevance()	Checks if the context is relevant to the given question (0 to 1) for multiple context chunks. Pass all context chunks as a list in the context column. Uses semantic similarity (default) or LLM. Aggregates relevance: mean (default) or hit (at least one chunk is relevant). Example: ContextRelevance("Question", "Context", output_scores=True, aggregation_method="hit", method="llm")	Required: input contexts Optional: output_scores: False or True method: semantic_similarity or llm aggregation_method: mean or hit aggregation_method_params={"threshold":0.95} (set the relevance threshold as greater or equal, 0.8 by default) alias provider model See LLM judge parameters.
FaithfulnessLLMEval()	Assesses whether the response stays faithful to the given context.Checks for hallucinations or unsupported claims. Returns a label (FAITHFUL or UNFAITHFUL) or a score. Run over the “response” column and pass the context column as a parameter. Example: FaithfulnessLLMEval("Response", context="Context")	Required: context Optional: alias provider model See LLM judge parameters.
CompletenessLLMEval()	Determines whether the response fully uses the information provided in the context. Returns a label (COMPLETE or INCOMPLETE) or a score. Run over the “response” column and pass the context column as a parameter. Example: CompletenessLLMEval("Response", context="Context")	Required: context Optional: alias provider model See LLM judge parameters.

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Generation

Evals for varied generation scenarios.

Name	Descriptor	Parameters
CorrectnessLLMEval()	Evaluates the correctness of a response by comparing it with the target output. Useful for RAG or any LLM generation where you have a ground truth output Returns a label (CORRECT or INCORRECT) or a score. Run over the “response” column and pass the target_output column as a parameter. Example: CorrectnessLLMEval("Response", target_output="Target")	Required: target_output Optional: alias provider model See LLM judge parameters.
DeclineLLMEval()	Detects if the text contains a refusal or rejection. Useful to detect instances where an LLM denies the user response. Returns a label (DECLINE or OK) or a score.	Optional: alias provider model See LLM judge parameters.
PIILLMEval()	Detects texts containing PII (Personally Identifiable Information). Returns a label (PII or OK) or a score.	Optional: alias provider model See LLM judge parameters.
NegativityLLMEval()	Detects negative texts. Returns a label (NEGATIVE or POSITIVE) or a score.	Optional: alias provider model See LLM judge parameters.
BiasLLMEval()	Detects biased texts. Returns a label (BIAS or OK) or a score.	Optional: alias provider model See LLM judge parameters.
ToxicityLLMEval()	Detects toxic texts. Returns a label (TOXICITY or OK) or a score.	Optional: alias provider model See LLM judge parameters.

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ML-based evals

Use pre-trained machine learning or embedding models.

Name	Descriptor	Parameters
SemanticSimilarity()	Calculates pairwise semantic similarity (Cosine Similarity) between two columns using a sentence embeddings model all-MiniLM-L6-v2. Returns a score from 0 to 1: (0: different, 0.5: unrelated, 1: identical) Example use: SemanticSimilarity(columns=["Question", "Answer"]).	Required: columns Optional: alias
BERTScore()	Calculates similarity between two text columns based on token embeddings. Returns BERTScore (F1 Score). Example use: BERTScore(columns=["Answer", "Target"]).	Required: columns Optional: model tfidf_weighted alias
Sentiment()	Analyzes text sentiment using a word-based model. Returns a score: -1 (negative) to 1 (positive).	Optional: alias
HuggingFace()	Scores the text using a user-selected HuggingFace model. See HuggingFace descriptor docs for example models.	Optional: alias See docs.
HuggingFaceToxicity()	Detects hate speech using a roberta-hate-speech model. Returns predicted probability for the “hate” label. Scale: 0 to 1.	Optional: toxic_label(default: hate) alias See docs.