Inferensys

Prompt

Argument Repair with Cross-Field Validation Rules Prompt Template

A practical prompt playbook for repairing tool call arguments where individual fields are valid but combinations violate business rules, using cross-field validation constraints in production AI workflows.
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PROMPT PLAYBOOK

When to Use This Prompt

Define the job, reader, and constraints for the Argument Repair with Cross-Field Validation Rules prompt.

This prompt is for integration engineers and agent platform developers who need to repair tool call arguments that pass individual field validation but fail cross-field business rules. The core job is to take a tool call, a set of cross-field constraints (like mutual exclusion, co-requirement, or conditional validity), and the original validation error, then produce a corrected argument set that satisfies all rules without breaking the tool's schema. This is not for fixing syntax errors or type mismatches—those are handled by separate repair prompts. Use this when your validation layer has already confirmed that each field is well-formed, but the combination of fields violates a higher-level rule.

The ideal user has a tool registry with defined schemas and a rules engine that can detect cross-field violations. You should have access to the original tool call arguments, the tool's JSON schema, the specific constraint that was violated, and the conversation context that led to the call. Do not use this prompt when the model itself should have known the business rules—if the rules were in the system prompt and the model ignored them, you have a prompt architecture problem, not a repair problem. Also avoid this prompt for simple type coercion or missing field recovery; those have dedicated playbooks with tighter scope and lower latency.

Before wiring this into production, define your constraint vocabulary precisely. Mutual exclusion, co-requirement, conditional validity, and range constraints should each have a standard error format that the repair prompt can parse. The prompt works best when the constraint violation message includes the specific fields involved and the rule that failed. If your validation layer only returns a generic 'invalid arguments' message, this prompt will guess rather than repair. Invest in structured validation errors first, then use this prompt as the recovery step. Always log the original arguments, the constraint violation, and the repaired output for audit and eval.

PRACTICAL GUARDRAILS

Use Case Fit

Where cross-field argument repair works, where it fails, and the operational prerequisites for deploying it safely in an agent loop.

01

Good Fit: Multi-Field Business Rules

Use when: individual arguments pass schema validation but violate combinatorial rules like mutual exclusion, co-requirement, or conditional validity. Guardrail: encode rules as explicit constraints in the repair prompt and validate the repaired output against the same rule engine before execution.

02

Bad Fit: Single-Field Type Errors

Avoid when: the failure is a simple type mismatch or syntax error in one field. Cross-field repair adds unnecessary complexity and latency. Guardrail: route single-field failures to a dedicated type coercion or JSON repair prompt first, and only invoke cross-field repair if those fail.

03

Required Input: Rule Definitions

What to watch: the model cannot infer business rules from a schema alone. Without explicit rule text, repairs will be guesswork. Guardrail: provide a structured [CONSTRAINTS] block listing each rule with its fields, condition, and violation message. Test that every rule is exercised in your eval set.

04

Required Input: Original Tool Call Context

What to watch: repairing arguments in isolation loses the user's intent and conversation history, leading to semantically correct but contextually wrong repairs. Guardrail: always pass the original [TOOL_CALL] payload and the preceding [CONVERSATION_CONTEXT] so the repair prompt can distinguish between user error and model error.

05

Operational Risk: False-Positive Constraint Violations

What to watch: the repair prompt may incorrectly flag a valid argument combination as a violation and 'fix' it, breaking a correct tool call. Guardrail: log every repair decision with the specific rule triggered. Implement a human review queue for repairs on high-stakes tool calls and track the false-positive rate over time.

06

Operational Risk: Repair Loop Exhaustion

What to watch: a cross-field repair can introduce a new violation that triggers another repair cycle, consuming the retry budget without converging. Guardrail: set a hard limit of 1-2 cross-field repair attempts per tool call. If the output still fails validation, escalate to a human or fall back to asking the user for clarification instead of looping indefinitely.

PROMPT PLAYBOOK

Copy-Ready Prompt Template

A reusable prompt template for repairing tool call arguments that violate cross-field validation rules, with placeholders for schema, error context, and business constraints.

This template is designed for integration engineers who need to fix tool calls where individual fields are syntactically valid but their combination violates business rules—such as mutually exclusive parameters being set together, co-required fields where one is missing, or conditional validity constraints. The prompt takes the original tool call, the validation error, the tool schema, and the cross-field rules, then produces a corrected argument set that satisfies all constraints. Use this when your agent loop receives a 422 Unprocessable Entity or custom business-logic rejection, not for simple type errors or missing required fields.

text
You are an argument repair assistant for an AI agent system. Your job is to fix tool call arguments that failed cross-field validation rules.

## TOOL SCHEMA
```json
[TOOL_SCHEMA]

CROSS-FIELD VALIDATION RULES

[RULES]

FAILED TOOL CALL

Tool: [TOOL_NAME] Arguments:

json
[FAILED_ARGUMENTS]

VALIDATION ERROR

[ERROR_MESSAGE]

CONVERSATION CONTEXT (if available)

[CONVERSATION_CONTEXT]

INSTRUCTIONS

  1. Identify which cross-field rule was violated based on the error message and the rules above.
  2. Determine the minimal set of changes needed to satisfy all rules while preserving the user's intent as expressed in the conversation context.
  3. If the conflict cannot be resolved without clarification, produce a clarification question instead of guessing.
  4. Output a JSON object with the following structure:

OUTPUT SCHEMA

json
{
  "status": "repaired" | "needs_clarification" | "unrepairable",
  "corrected_arguments": { /* the fixed arguments object, or null if not repaired */ },
  "changes_made": ["description of each change"],
  "clarification_question": "question to ask the user, if status is needs_clarification",
  "confidence": 0.0_to_1.0
}

CONSTRAINTS

  • Do not add fields that are not in the tool schema.
  • Do not remove fields that were explicitly provided unless required by a rule.
  • Prefer the user's explicit values over inferred defaults.
  • If multiple repairs are possible, choose the one that requires the fewest changes.
  • For [RISK_LEVEL] risk operations, flag the repair for human review even if confidence is high.

To adapt this template, replace the square-bracket placeholders with your actual values. [TOOL_SCHEMA] should contain the complete JSON Schema or OpenAPI parameter definition for the tool. [RULES] should enumerate each cross-field constraint in plain language—for example, "start_date must be before end_date" or "payment_method: wire requires routing_number to be present." [FAILED_ARGUMENTS] is the exact JSON the model produced that triggered the error. [ERROR_MESSAGE] is the raw validation error from your API or business logic layer. [CONVERSATION_CONTEXT] is optional but strongly recommended; include the last few turns of the conversation so the repair prompt can infer user intent rather than making blind edits. [RISK_LEVEL] should be set to high, medium, or low to control whether the repair requires human approval before execution.

Before deploying, test this prompt against a golden set of known cross-field violations with expected repairs. Common failure modes include: the model removing a valid field instead of the conflicting one, producing a repair that passes validation but changes the user's intent, or failing to detect that clarification is needed and guessing incorrectly. For high-risk domains such as financial transactions or healthcare operations, always route status: repaired outputs with confidence below 0.9 to a human review queue. Wire the needs_clarification status back into your agent loop so the system can ask the user and retry with the clarified input.

IMPLEMENTATION TABLE

Prompt Variables

Required inputs for the cross-field validation repair prompt. Each placeholder must be populated before the repair loop executes. Missing or malformed inputs cause the repair to fail silently or introduce new violations.

PlaceholderPurposeExampleValidation Notes

[ORIGINAL_ARGUMENTS]

The tool call arguments that passed individual field validation but failed cross-field rules

{"start_date": "2025-06-01", "end_date": "2025-05-15", "discount_type": "percentage", "discount_value": null}

Must be valid JSON. Parse check before prompt assembly. Null values allowed but will trigger co-requirement rules.

[TOOL_SCHEMA]

Complete tool definition including parameter types, descriptions, and any field-level constraints

{"name": "apply_discount", "parameters": {"type": "object", "properties": {"discount_type": {"type": "string", "enum": ["percentage", "fixed"]}, "discount_value": {"type": "number"}}, "required": ["discount_type"]}}

Schema must be valid JSON Schema or OpenAPI fragment. Validate structural integrity before use. Enum definitions required for enum normalization.

[CROSS_FIELD_RULES]

Explicit list of cross-field validation rules that failed, with rule type and description

["RULE: mutual_exclusion — 'percentage' and 'fixed' discount_type cannot both have non-null discount_value", "RULE: co_requirement — discount_type 'percentage' requires discount_value between 0 and 100", "RULE: temporal_order — start_date must be before end_date"]

Each rule must specify type (mutual_exclusion, co_requirement, conditional_validity, temporal_order, set_constraint) and human-readable description. Minimum one rule required.

[CONVERSATION_CONTEXT]

Recent conversation turns or agent reasoning that led to the tool call, used to infer correct intent when rules conflict

"User asked for a 15% discount on the annual plan starting June 1st. Agent selected percentage discount type."

Optional but strongly recommended. Null allowed if no context available. Truncate to last 3-5 turns to avoid noise. Context must be plain text or structured transcript.

[REPAIR_STRATEGY]

Instruction for how to resolve ambiguous rule violations: prefer user intent, safest default, or ask for clarification

"prefer_user_intent"

Must be one of: prefer_user_intent, safest_default, escalate_for_clarification, preserve_most_fields. Controls repair behavior when multiple valid fixes exist.

[MAX_REPAIR_ATTEMPTS]

Integer capping the number of repair iterations before escalation

3

Must be positive integer. Recommended range 1-5. Used by harness to track retry budget, not embedded in prompt text directly.

[PREVIOUS_REPAIR_RESULTS]

Array of prior repair attempts and their validation outcomes, used to avoid repeating failed strategies

[{"attempt": 1, "repaired_arguments": {"start_date": "2025-06-01", "end_date": "2025-06-01"}, "remaining_violations": ["temporal_order — start_date equals end_date"]}]

Null on first attempt. Each entry must contain repaired_arguments and remaining_violations. Harness appends after each failed repair cycle.

PROMPT PLAYBOOK

Implementation Harness Notes

How to wire the cross-field argument repair prompt into an agent loop or validation pipeline.

This prompt is designed to sit directly behind a failed validation step in a tool-call execution pipeline. When a model generates a function call that passes individual field validation but fails a cross-field business rule check, the application should catch the rule violation, package the failure context, and invoke this repair prompt before retrying execution. The prompt expects the original arguments, the tool schema, and the specific cross-field constraint that was violated. It is not a general-purpose repair prompt—it assumes individual fields are already type-valid and focuses exclusively on resolving inter-field conflicts like mutual exclusion, co-requirement, or conditional validity.

To wire this into an application, implement a validation middleware that runs after the model's tool call is parsed but before the function is executed. The middleware should first run standard schema validation (type checks, required fields, enum membership). If that passes, it should then apply your cross-field rule engine. When a rule fails, capture the rule name, the fields involved, the constraint description, and the violation reason. Pass these into the prompt's [CROSS_FIELD_RULES] and [VIOLATION_DETAILS] placeholders alongside the original [TOOL_CALL_ARGUMENTS] and [TOOL_SCHEMA]. The model will return a repaired argument payload. Before executing it, re-run the same cross-field validation to confirm the repair resolved the violation. If it fails again, increment a retry counter and consider escalating to a human or a fallback model after 2-3 attempts. Log every repair attempt with the original arguments, the violated rule, the repaired arguments, and the re-validation result for debugging and eval.

For high-stakes workflows—financial transactions, clinical actions, or irreversible API calls—add a human approval gate after repair. Even if the repaired arguments pass cross-field validation, queue them for review if the repair changed a semantically significant field (e.g., swapping a refund action for a void action to satisfy a mutual exclusion rule). Track which fields were modified by the repair prompt using a structural diff, and flag any repair that alters more than one field or changes a field to a value not present in the original conversation context. For eval, build a test suite of known cross-field violations with expected repairs, and measure both repair success rate (did re-validation pass?) and semantic preservation rate (did the repair change the user's intent?). Use a separate LLM judge prompt to compare the original and repaired arguments for intent drift.

IMPLEMENTATION TABLE

Expected Output Contract

Fields, format, and validation rules for the repaired tool call output. Use this contract to validate the repair prompt's response before executing the corrected function call.

Field or ElementType or FormatRequiredValidation Rule

repaired_tool_call

object

Must be a valid JSON object matching the target tool's schema. Parse check required.

repaired_tool_call.name

string

Must exactly match an available tool name from [TOOL_REGISTRY]. Case-sensitive exact match.

repaired_tool_call.arguments

object

Must be a valid JSON object. All keys must exist in the tool's parameter schema. No extra keys allowed.

repair_annotations

array

Must be an array of objects, each with field, original_value, repaired_value, rule_applied, and confidence. Minimum 1 entry if any repair occurred.

repair_annotations[].field

string

Must reference a valid argument path using dot notation matching the tool schema. Path must exist in the original failing call.

repair_annotations[].rule_applied

string

Must be one of the cross-field constraint rule names from [CROSS_FIELD_RULES]. No invented rule names allowed.

repair_annotations[].confidence

number

Must be a float between 0.0 and 1.0 inclusive. Values below [CONFIDENCE_THRESHOLD] should trigger human review.

cross_field_violations_resolved

array

Must list every violation from [VALIDATION_ERRORS] that was addressed. Empty array if no cross-field violations were present.

PRACTICAL GUARDRAILS

Common Failure Modes

Cross-field validation repair fails in predictable ways. Here are the most common failure modes when fixing tool calls where individual fields are valid but combinations violate business rules, and how to guard against them.

01

Single-Field Tunnel Vision

What to watch: The repair prompt fixes one violating field but breaks another constraint in the process, creating a whack-a-mole cycle. This happens when cross-field rules are listed independently without the model reasoning about their interactions. Guardrail: Include a pre-repair constraint analysis step that lists all active rules before any field is modified. Validate the full argument set after repair, not just the originally failing field.

02

Mutual Exclusion Over-Correction

What to watch: When fields A and B are mutually exclusive and both are present, the repair prompt removes one arbitrarily without considering which one better matches the user's intent or conversation context. Guardrail: Provide a tie-breaking heuristic in the prompt—prefer the field with stronger contextual support, or the one that appears later in the conversation if intent is ambiguous. Log the removal decision for audit.

03

Co-Requirement Cascade Failure

What to watch: A co-requirement rule says "if field X is present, field Y must also be present." The repair prompt adds Y with a hallucinated or default value that passes structural validation but is semantically wrong. Guardrail: Require the repair prompt to source co-required values from conversation context or explicit user input only. If no source exists, escalate to a clarification request rather than inventing a value.

04

Conditional Validity Blindness

What to watch: A field's valid range depends on another field's value (e.g., max_amount depends on currency). The repair prompt applies a generic range clamp without checking the condition, producing a value that is structurally valid but logically incorrect for the given context. Guardrail: Structure conditional rules as explicit if-then blocks in the prompt. Include a post-repair conditional re-check that verifies the dependent field against the resolved condition.

05

False-Positive Constraint Violation Flagging

What to watch: The validation layer flags a combination as invalid, but the repair prompt cannot determine why, so it makes unnecessary or destructive changes to fields that were already correct. This erodes trust and wastes retry budget. Guardrail: Include the specific violated rule name and the fields involved in the error message passed to the repair prompt. Never pass a generic "invalid combination" message without the constraint that failed.

06

Retry Budget Exhaustion on Unresolvable Combinations

What to watch: Some cross-field violations are genuinely unresolvable because the user's request is contradictory. The repair loop burns through all retries attempting impossible fixes instead of escalating early. Guardrail: Track the number of distinct constraint violations across retries. If the same set of rules fails twice or the violation count increases after a repair, stop retrying and escalate to a human or clarification prompt immediately.

IMPLEMENTATION TABLE

Evaluation Rubric

Use this rubric to test whether the Argument Repair with Cross-Field Validation Rules prompt consistently produces correct, safe, and complete repairs before shipping to production.

CriterionPass StandardFailure SignalTest Method

Cross-field rule coverage

All violated cross-field constraints from [RULE_SET] are explicitly addressed in the repair output

A known violated rule is ignored or the repair introduces a new cross-field violation

Run against a golden set of 20 argument payloads with seeded cross-field violations; check that every seeded violation is resolved

No valid field corruption

Fields that were individually valid and not involved in a cross-field violation remain unchanged

A previously valid field value is altered, removed, or corrupted during repair

Diff the input [INVALID_ARGUMENTS] against the repaired output; flag any changes to fields not listed in [VIOLATION_DETAILS]

False-positive avoidance

The prompt does not flag or modify argument combinations that satisfy all cross-field rules

A valid argument set is incorrectly identified as violating a constraint and is modified unnecessarily

Submit 10 valid argument payloads; assert that the repair output is identical to the input or explicitly states no repair needed

Schema compliance post-repair

The repaired arguments pass validation against the original [TOOL_SCHEMA] including all field types and required constraints

The repaired output fails schema validation due to type mismatch, missing required field, or extra field

Validate every repair output against the JSON Schema definition; fail the test if any validation error is returned

Rule explanation accuracy

The repair output includes a correct citation of which specific rule from [RULE_SET] was violated and how it was resolved

The explanation references a non-existent rule, misidentifies the violated constraint, or provides a contradictory resolution

Parse the explanation field; verify the cited rule ID exists in [RULE_SET] and the resolution logic matches the rule definition

Mutual exclusion enforcement

When two fields are mutually exclusive per [RULE_SET], the repair removes exactly one and preserves the other

Both mutually exclusive fields remain present, or both are removed, or the wrong field is removed

Seed test cases with mutual exclusion violations; assert exactly one of the conflicting fields is present in the output

Co-requirement enforcement

When [RULE_SET] requires field B if field A is present, the repair either adds B or removes A

Field A is present without required field B, or an unrelated field is modified instead

Seed test cases with missing co-required fields; assert the output satisfies the co-requirement constraint

Conditional validity enforcement

When a field's validity depends on another field's value per [RULE_SET], the repair adjusts the dependent field or the controlling field to restore consistency

The conditional constraint remains violated, or the repair breaks a different constraint while fixing the conditional one

Seed test cases with conditional validity violations; assert the output satisfies the condition defined in [RULE_SET]

ADAPTATION OPTIONS

Adapt This Prompt

How to adapt

Start with the base cross-field validation rules defined as a simple list in the prompt. Use a single model call that receives the original arguments, the validation error, and the rule set. Keep the output format loose—accept a corrected JSON object without strict schema enforcement.

code
You are repairing tool call arguments that failed cross-field validation.

Original arguments: [ORIGINAL_ARGS]
Validation error: [ERROR_MESSAGE]
Cross-field rules: [RULES_LIST]

Return corrected arguments as JSON.

Watch for

  • Rules expressed in prose rather than explicit constraints
  • Model ignoring one rule to satisfy another
  • No tracking of which rule triggered the original failure
  • Over-correction that breaks previously valid fields
Prasad Kumkar

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.