This prompt is designed for agent developers and AI reliability engineers who need to move beyond surface-level eval failures and identify the root cause in their tool-call layer. The core job-to-be-done is connecting a failed automated evaluation to a specific, upstream tool error within the same trace. Instead of manually inspecting logs, you provide structured tool-call logs and eval results, and the prompt produces a correlation matrix that maps tool errors to the eval dimensions they broke, complete with a severity score. The ideal user has access to trace-level observability data and is responsible for prioritizing engineering fixes in a complex agent pipeline.
Prompt
Tool-Call Error Correlation with Eval Failure Prompt

When to Use This Prompt
Understand when to deploy the tool-call error correlation prompt for offline batch analysis of agent traces.
Use this prompt when you have completed traces that contain both the tool-call execution details and the final automated evaluation scores. It is built for offline batch analysis, making it suitable for a weekly review of production failures or a post-deployment quality audit. The required context is strict: you must supply structured data for both [TOOL_CALL_LOG] and [EVAL_RESULTS] from the same trace. The prompt is not designed for real-time intervention on a live agent. Do not use it if your goal is to fix a single, in-flight conversation or if your eval data lacks trace-level attribution. It is also not a replacement for a real-time monitoring dashboard; its value is in systematic, batched root-cause analysis.
Before using this prompt, ensure your observability pipeline is capturing the necessary data. The tool-call log must include timestamps, function names, arguments, and error codes or success states. The eval results must be structured with named dimensions (e.g., 'faithfulness', 'completeness') and a clear pass/fail or numeric score. If your traces are incomplete or your evals are unstructured, the prompt will produce a low-confidence or incomplete matrix. The next step after running this analysis is to take the prioritized list of tool-eval correlations and use it to plan engineering work, such as hardening a specific API integration or adding argument validation before a tool call.
Use Case Fit
Where the Tool-Call Error Correlation with Eval Failure Prompt works and where it introduces risk. Use this playbook when you have structured trace data linking tool calls to eval scores; avoid it when logs are incomplete or the failure is clearly a reasoning error.
Good Fit: Structured Agent Traces
Use when: you have complete, structured traces containing both tool-call logs (with success/failure/error codes) and downstream eval scores for the same trace_id. The prompt excels at producing a correlation matrix when the data is machine-readable and step-level attribution is possible.
Bad Fit: Missing or Unstructured Logs
Avoid when: tool-call logs are unstructured text blobs, eval scores are not linked to specific traces, or error codes are missing. The prompt cannot fabricate correlations from absent data and will produce a low-confidence or misleading matrix if forced to guess.
Required Inputs
Must provide: a set of traces with trace_id, tool_call blocks (including tool_name, status, error_code, timestamp), and eval_result blocks (including dimension, score, threshold). Without these fields, the correlation engine has nothing to join.
Operational Risk: Spurious Correlation
What to watch: the model may identify a correlation between a tool error and an eval failure that is coincidental, not causal. Guardrail: require the output matrix to include a confidence score and a causal_path explanation for each high-severity link. Flag low-confidence correlations for human review before acting on them.
Operational Risk: Severity Inflation
What to watch: the prompt may assign high severity to tool errors that are expected or gracefully handled, inflating the perceived impact. Guardrail: provide a tool_error_tolerance map in the input that defines which error codes are expected and should be excluded from severity scoring.
Operational Risk: Eval Dimension Blindness
What to watch: the correlation matrix may miss tool errors that cause eval failures in dimensions not explicitly listed in the eval schema. Guardrail: include an eval_dimension_catalog in the prompt input that defines all possible eval dimensions, and instruct the model to flag any tool error that correlates with an unlisted dimension as an unknown propagation risk.
Copy-Ready Prompt Template
A reusable prompt template with square-bracket placeholders for correlating tool-call errors with downstream eval failures in production traces.
This prompt template is designed to be pasted directly into your observability pipeline, batch analysis script, or manual trace review workflow. It accepts structured tool-call logs and eval results from a single trace and produces a correlation matrix showing which tool errors propagated to which eval dimensions, along with severity scoring. The template uses square-bracket placeholders that you must replace with actual data before execution. All placeholders are mandatory unless marked optional in the adaptation notes below.
textYou are an AI reliability engineer analyzing a production trace where an agent's tool calls may have caused downstream evaluation failures. ## INPUT DATA ### Tool-Call Log [TOOL_CALL_LOG] ### Eval Results [EVAL_RESULTS] ### Trace Metadata (Optional) [TRACE_METADATA] ## OUTPUT SCHEMA Return a JSON object with this exact structure: { "correlation_matrix": [ { "tool_call_id": "string", "tool_name": "string", "error_type": "string | null", "error_severity": "critical | high | medium | low | none", "affected_eval_dimensions": [ { "dimension_name": "string", "impact_severity": "critical | high | medium | low", "causal_chain": "string explaining how the tool error caused the eval failure", "evidence_from_trace": "string citing specific trace events" } ], "recovery_possible": true | false, "recovery_suggestion": "string | null" } ], "unaffected_eval_failures": [ { "dimension_name": "string", "failure_reason": "string explaining why this failure is NOT attributable to tool errors", "alternative_root_cause_hypothesis": "string" } ], "summary": { "total_tool_calls": number, "tool_calls_with_errors": number, "total_eval_failures": number, "eval_failures_explained_by_tool_errors": number, "dominant_failure_pattern": "string", "recommended_action": "string" } } ## CONSTRAINTS [CONSTRAINTS] ## ANALYSIS RULES 1. For each tool call in the log, determine if it produced an error (timeout, malformed arguments, unexpected response, missing required fields, permission denial, empty result). 2. For each tool error, trace forward through the trace to identify which eval dimensions were affected. 3. A causal chain must reference specific trace events (timestamps, step IDs, log lines) as evidence. 4. If a tool call succeeded but the eval still failed, classify those failures under "unaffected_eval_failures" with alternative hypotheses. 5. Severity scoring: "critical" means the eval failure makes the response unusable; "high" means significant quality degradation; "medium" means noticeable but not blocking; "low" means minor impact. 6. If [RISK_LEVEL] is "high", flag any correlation where tool errors affected safety, compliance, or factual accuracy dimensions for immediate human review. ## EXAMPLES [EXAMPLES]
Adaptation notes: Replace [TOOL_CALL_LOG] with a structured JSON array of tool-call events including timestamps, tool names, arguments, responses, and error fields. Replace [EVAL_RESULTS] with a JSON array of eval dimension scores, thresholds, and failure flags. [TRACE_METADATA] is optional but should include trace ID, session ID, model version, and prompt version when available. [CONSTRAINTS] should specify any domain-specific rules, such as "ignore timeout errors under 200ms" or "treat citation failures as critical." [EXAMPLES] should include 1-2 few-shot examples of correct correlation matrices from your own production traces to improve output consistency. [RISK_LEVEL] should be set to "high" when analyzing traces from regulated domains, safety-critical systems, or customer-facing financial decisions. For high-risk traces, always route the output to a human reviewer before taking automated action such as prompt rollback or tool reconfiguration.
Prompt Variables
Required inputs for the Tool-Call Error Correlation with Eval Failure Prompt. Each variable must be extracted from structured trace logs and eval results before the prompt is assembled. Missing or malformed inputs will cause the correlation matrix to be incomplete or misleading.
| Placeholder | Purpose | Example | Validation Notes |
|---|---|---|---|
[TRACE_ID_LIST] | Unique identifiers for the production traces to analyze. Each trace must contain both tool-call events and eval results from the same session. | trace_4a2f91b, trace_7c3e0d5, trace_9b1f662 | Must be a non-empty list of valid trace IDs. Each ID must resolve to a trace with at least one tool-call event and one eval score. Reject if any trace ID returns null or empty data. |
[TOOL_CALL_LOG] | Structured log of tool invocations per trace, including tool name, arguments, response status, error codes, and timestamps. | {"trace_id": "trace_4a2f91b", "calls": [{"tool": "search_kb", "status": "error", "error_code": "TIMEOUT", "step": 3}]} | Must be valid JSON with a calls array per trace. Each call object requires tool, status, and step fields. Status must be one of success, error, or partial. Reject if error_code is present but status is not error. |
[EVAL_RESULTS] | Per-trace evaluation scores across all eval dimensions, including dimension name, score, threshold, and pass/fail verdict. | {"trace_id": "trace_4a2f91b", "evals": [{"dimension": "faithfulness", "score": 0.32, "threshold": 0.70, "verdict": "fail"}]} | Must be valid JSON with an evals array per trace. Each eval object requires dimension, score, threshold, and verdict fields. Score must be a float between 0.0 and 1.0. Verdict must be pass or fail. Reject if score exceeds 1.0 or dimension name is empty. |
[EVAL_DIMENSION_NAMES] | List of eval dimensions to include in the correlation matrix. Used to filter and scope the analysis. | ["faithfulness", "answer_relevance", "citation_accuracy", "completeness"] | Must be a non-empty array of strings. Each dimension name must match a dimension present in [EVAL_RESULTS] for at least one trace. Warn if a dimension appears in the list but has no failing traces. |
[TOOL_ERROR_SEVERITY_MAP] | Optional mapping of tool error codes to severity levels for weighting the correlation. Defaults to uniform severity if not provided. | {"TIMEOUT": "high", "INVALID_ARG": "medium", "EMPTY_RESULT": "low"} | If provided, must be a valid JSON object mapping error_code strings to one of high, medium, or low. Null values allowed if severity is unknown. Reject if severity value is not in the allowed set. |
[MIN_CORRELATION_THRESHOLD] | Minimum correlation strength to include a tool-error-to-eval-dimension pair in the output matrix. Filters out noise. | 0.3 | Must be a float between 0.0 and 1.0. Default to 0.2 if not provided. Reject if value is negative or greater than 1.0. Warn if threshold is set above 0.8 as it may suppress meaningful weak signals. |
[TRACE_TIMESTAMP_RANGE] | Optional time window to scope the analysis. Used to exclude stale traces or isolate a regression period. | {"start": "2025-03-01T00:00:00Z", "end": "2025-03-15T23:59:59Z"} | If provided, must be a valid JSON object with start and end fields in ISO 8601 format. Both fields required if range is specified. Reject if end is before start. Null allowed for open-ended ranges. |
[OUTPUT_FORMAT] | Desired output structure for the correlation matrix. Controls whether the prompt returns a flat list, nested matrix, or both. | nested_matrix_with_flat_export | Must be one of flat_list, nested_matrix, or nested_matrix_with_flat_export. Default to nested_matrix if not provided. Reject if value is not in the allowed set. |
Implementation Harness Notes
How to wire the correlation prompt into a production observability pipeline with structured logs, validation, and actionable output.
This prompt is designed to be called programmatically as part of an automated incident review or periodic quality audit workflow, not as a one-off chat interaction. The harness must supply structured tool-call logs and eval results from the same trace, formatted as the [TOOL_CALL_LOG] and [EVAL_RESULTS] inputs. These inputs should be extracted directly from your observability platform (e.g., LangSmith, Arize, Weights & Biases, or a custom trace store) and injected into the prompt template without manual reformatting. The prompt expects JSON arrays for both inputs, where each tool call includes tool_name, input_args, output_summary, error_code, and timestamp, and each eval result includes eval_name, score, threshold, pass_fail, and eval_dimension. If your trace store uses a different schema, build a thin transformation layer that normalizes the data before prompt assembly—do not ask the model to guess field mappings.
The implementation should include a validation wrapper around the model's JSON output. The expected output schema is a correlation matrix with tool_errors, eval_failures, correlations, and severity_summary objects. Before the output reaches any downstream dashboard or alerting system, validate that: (1) every tool_error_id in the correlations array exists in the tool_errors list, (2) every eval_failure_id exists in the eval_failures list, (3) severity_score values are integers between 1 and 5, and (4) the propagation_path field is a non-empty string. If validation fails, retry the prompt once with the validation errors appended as a [CONSTRAINTS] note. If the retry also fails, log the raw output and escalate for human review rather than silently ingesting malformed correlation data. For high-stakes production systems where eval failures trigger rollbacks or incident alerts, add a human approval step before the correlation matrix is used to generate automated remediation actions.
Model choice matters here. The prompt requires strong JSON-following behavior and the ability to reason across two structured datasets simultaneously. Use a model with proven structured output reliability (e.g., GPT-4o, Claude 3.5 Sonnet, or equivalent) and set temperature=0 to minimize variance in severity scoring. If you are processing high volumes of traces, batch multiple trace pairs into a single prompt call where each trace gets its own correlation analysis, but keep batch sizes small (3–5 traces) to avoid context-window pressure that degrades correlation accuracy. Log every prompt call with the trace ID, model version, input hashes, and output correlation matrix for auditability. This log becomes essential evidence when the correlation prompt itself is suspected of misattributing an eval failure to the wrong tool error.
Expected Output Contract
Defines the structure, types, and validation rules for the tool-call error correlation matrix output. Use this contract to parse, validate, and store the prompt result before downstream analysis or dashboard display.
| Field or Element | Type or Format | Required | Validation Rule |
|---|---|---|---|
correlation_matrix | Array of objects | Must be a JSON array. Each element must conform to the correlation_entry schema. Array length must be > 0. | |
correlation_entry.tool_name | String | Must match a tool name present in the input [TOOL_CALL_LOG]. Non-empty string. | |
correlation_entry.tool_error_type | String | Must be one of: 'timeout', 'invalid_arguments', 'execution_failure', 'permission_denied', 'empty_result', 'rate_limited'. Case-sensitive enum check. | |
correlation_entry.eval_dimension | String | Must match a dimension name from the input [EVAL_RESULTS]. Non-empty string. | |
correlation_entry.severity_score | Number (float) | Must be a float between 0.0 and 1.0 inclusive. 0.0 = no correlation, 1.0 = direct causation. Parse as float and check bounds. | |
correlation_entry.evidence_trace_ids | Array of strings | Must be an array of trace IDs from the input [TRACE_DATA]. Each ID must be a non-empty string. Array length must be >= 1. | |
correlation_entry.rationale | String | Must be a non-empty string explaining the causal link between the tool error and the eval failure. Max 500 characters. | |
summary.highest_severity_pair | Object (correlation_entry) | Must be the single correlation_entry with the highest severity_score. If multiple ties, include the first encountered. |
Common Failure Modes
When correlating tool-call errors with eval failures, these are the most common failure modes that break the analysis before it delivers value. Each card explains what to watch for and how to guard against it.
Missing Trace Attribution
What to watch: Tool-call errors and eval failures are logged in separate systems with no shared trace ID, making correlation impossible. The prompt produces a matrix full of 'unknown' entries because it cannot link events from the same request. Guardrail: Require a unified trace ID propagated across tool-call logs, eval results, and model responses before running this prompt. Validate trace completeness as a pre-processing step.
Spurious Correlation Overfitting
What to watch: The prompt identifies correlations between tool errors and eval failures that are statistically coincidental rather than causal. A tool timeout and a factual accuracy failure may appear together in traces without the timeout causing the inaccuracy. Guardrail: Require the prompt to output a confidence score and a causal mechanism hypothesis for each correlation. Flag correlations with fewer than [MIN_SAMPLE_COUNT] co-occurrences as low-confidence. Human review required for severity scores above [SEVERITY_THRESHOLD].
Eval Rubric Misalignment
What to watch: The eval dimensions in the rubric do not map cleanly to tool-call error types. For example, a 'helpfulness' eval score may drop because a search tool returned empty results, but the rubric has no category for retrieval gaps. The correlation matrix becomes misleading because failures are attributed to the wrong root cause. Guardrail: Pre-validate that each eval dimension has at least one plausible tool-error cause before running correlation. If gaps exist, flag the eval rubric for revision rather than forcing a correlation.
Temporal Lag Masking
What to watch: A tool-call error in an early step of an agent trace causes a downstream eval failure several steps later. The correlation prompt may miss the connection because it only examines adjacent steps or single-turn pairs. Guardrail: Configure the prompt to analyze full trace sequences, not just adjacent events. Include a propagation window parameter [MAX_PROPAGATION_STEPS] that defines how far back to search for root-cause tool errors. Output should include a propagation path, not just a pairwise correlation.
Severity Score Inflation
What to watch: The prompt assigns high severity scores to every correlation because it treats all eval failures as equally critical. A minor formatting drift gets the same severity as a factual hallucination, making the matrix useless for prioritization. Guardrail: Provide a severity calibration rubric that defines what constitutes critical, high, medium, and low severity based on user impact, not just eval score magnitude. Require the prompt to justify each severity assignment with a specific impact statement.
Silent Tool Failures
What to watch: A tool returns a technically valid but semantically wrong result without throwing an error code. The tool-call log shows success, but the downstream eval fails because the tool provided incorrect data. The correlation matrix shows no tool error for that eval failure, leading to a false negative. Guardrail: Extend the input schema to include tool output validation checks, not just error codes. If a tool returned results but those results contradict retrieved evidence or expected schema, flag it as a silent failure before correlation analysis begins.
Evaluation Rubric
Criteria for validating the correlation matrix output before integrating it into a production monitoring pipeline or incident review process.
| Criterion | Pass Standard | Failure Signal | Test Method |
|---|---|---|---|
Tool-call coverage | Every tool-call error in the input trace is represented in the correlation matrix | Missing tool-call errors or tool calls without error classification | Parse the output matrix and assert that the set of tool_call_ids matches the input trace |
Eval dimension coverage | Every eval dimension from the input eval result is represented as a column in the matrix | Missing eval dimensions or dimensions renamed without mapping | Extract column headers and assert set equality with eval dimension names from the input |
Severity score range | All severity scores are integers between 1 and 5 inclusive | Scores outside 1-5, non-integer values, or null scores | Validate each cell value with a range check and type assertion |
Propagation path completeness | Every non-zero severity cell includes a propagation_path string referencing a trace span | Non-zero severity cells with null, empty, or missing propagation_path | For each cell where severity > 0, assert propagation_path is a non-empty string matching a span_id in the trace |
Root-cause classification | Each tool-call error row includes exactly one root_cause_category from the allowed enum | Missing root_cause_category, multiple categories, or value outside allowed enum | Validate root_cause_category against the allowed enum: [ARGUMENT_ERROR, TOOL_UNAVAILABLE, TIMEOUT, PERMISSION_DENIED, MALFORMED_RESPONSE, UNKNOWN] |
Correlation confidence threshold | All correlation entries with confidence below 0.7 are flagged with requires_human_review: true | Low-confidence correlations without review flag | For each cell where confidence < 0.7, assert requires_human_review is true |
Output schema compliance | The output matches the [OUTPUT_SCHEMA] exactly with all required fields present | Missing required fields, extra fields, or type mismatches | Validate the full output against the JSON schema using a schema validator |
Trace-to-matrix traceability | Every correlation entry includes a trace_id matching the input trace | Mismatched or missing trace_id values | Assert that all trace_id values in the output match the input trace identifier |
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Adapt This Prompt
How to adapt
Start with the base correlation prompt but relax strict schema requirements. Accept a markdown table or bulleted list instead of enforcing the full JSON correlation matrix. Use a smaller sample of traces (5-10) to validate the approach before scaling.
Prompt modification
Replace [OUTPUT_SCHEMA] with: "Return a markdown table with columns: Tool Error, Eval Dimension, Correlation Strength (Low/Medium/High), Severity (1-5), Evidence Trace ID."
Watch for
- The model conflating correlation with causation without trace evidence
- Missing severity justification when tool errors are intermittent
- Overly broad correlation claims without per-trace linking

About the author
Prasad Kumkar
CEO & MD, Inference Systems
Prasad Kumkar is the CEO & MD of Inference Systems and writes about AI systems architecture, LLM infrastructure, model serving, evaluation, and production deployment. Over 5+ years, he has worked across computer vision models, L5 autonomous vehicle systems, and LLM research, with a focus on taking complex AI ideas into real-world engineering systems.
His work and writing cover AI systems, large language models, AI agents, multimodal systems, autonomous systems, inference optimization, RAG, evaluation, and production AI engineering.
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