Inferensys

Prompt

Tool Call Execution Plan Validation Prompt for Dependencies

A practical prompt playbook for pre-validating tool call orchestration plans before execution, producing a pass/fail assessment with specific violation details for automated rejection.
Control room desk with laptops and a large orchestration network display.
PROMPT PLAYBOOK

When to Use This Prompt

A pre-execution gate for platform engineers to validate tool call plans against dependency, ordering, and resource conflict rules before any tool runs.

This prompt is a pre-execution validation gate for agent infrastructure. It accepts a proposed list of tool calls—each with declared inputs, outputs, and dependency relationships—and returns a structured pass/fail assessment. The primary job-to-be-done is preventing incorrect parallelization, race conditions, and inconsistent state before the execution engine dispatches any tool. Platform engineers and agent infrastructure teams use this prompt in the orchestration layer, positioned after a planner or agent proposes tool calls but before the execution engine runs them. It is not a runtime recovery prompt, a retry handler, or a tool output interpreter.

Use this prompt when your agent system generates multi-tool execution plans and you need automated validation of dependency correctness. Required context includes the full list of proposed tool calls, each tool's declared input-output signature, and any explicit dependency annotations (e.g., requires-output-of, conflicts-with, must-follow). The prompt checks for missing dependencies, circular references, resource conflicts, ordering constraint violations, and read-after-write hazards. It produces a structured error report suitable for automated rejection or human review. Do not use this prompt for single-tool calls, for runtime error recovery after execution has started, or for validating the semantic correctness of tool outputs—those belong to separate playbooks.

This prompt belongs in a pre-execution middleware layer. Wire it so that any plan failing validation is blocked with a detailed violation report, not silently executed. For high-risk domains—such as financial transactions, healthcare operations, or infrastructure mutations—require human approval on any plan that triggers a FAIL or CONDITIONAL_PASS result. The prompt works best with models that support structured output and tool-use reasoning (e.g., GPT-4, Claude 3.5 Sonnet). Avoid using smaller or instruction-untuned models for this task, as they may miss subtle dependency violations. After validation passes, hand the approved plan to your execution engine with confidence that ordering and dependency constraints are satisfied.

PRACTICAL GUARDRAILS

Use Case Fit

Where this prompt works, where it fails, and what you must have in place before relying on it in a production pipeline.

01

Good Fit: Pre-Execution Gate in CI/CD

Use when: you have a generated execution plan (DAG) and need a deterministic pass/fail check before any tool runs. Guardrail: Run this prompt synchronously in your CI pipeline or pre-flight hook. Reject the plan on failure; never execute a plan that fails validation.

02

Good Fit: Multi-Tool Agent Sandbox

Use when: an agent proposes a sequence of tool calls and you need to catch circular dependencies or missing inputs before side effects occur. Guardrail: Treat the validation output as a hard block. Log the structured error report for the agent's next planning attempt.

03

Bad Fit: Real-Time Single-Turn Decisions

Avoid when: latency budget is under 500ms and the plan is trivial (1-2 tools). The validation overhead outweighs the risk. Guardrail: Use a lightweight, rule-based dependency checker for simple cases. Reserve this prompt for complex, multi-step plans.

04

Bad Fit: Undefined Tool Schemas

Avoid when: your tool definitions lack explicit input/output schemas with declared dependencies. The model cannot validate what it cannot see. Guardrail: Enforce a tool registration contract that includes requires_output_of and resource fields before applying this prompt.

05

Required Input: Structured Execution Plan

Risk: Feeding the prompt a natural language description of steps instead of a machine-parsable plan leads to hallucinated violations. Guardrail: Always provide a JSON or YAML plan with explicit tool_name, arguments, and depends_on fields. Validate the plan's schema before sending it to this prompt.

06

Operational Risk: False Positives on Complex State

Risk: The model may flag a dependency violation when a resource is managed by an external transaction manager or eventual consistency model it doesn't understand. Guardrail: Implement an allowlist for known safe patterns and a human review queue for plans that fail validation but are submitted with an override reason.

PROMPT PLAYBOOK

Copy-Ready Prompt Template

A reusable prompt that validates a proposed tool call execution plan for dependency violations before any tool runs.

This prompt template is designed to be pasted directly into your orchestration layer. It accepts a proposed execution plan—a list of tool calls with their inputs and declared dependencies—and returns a structured pass/fail assessment. The model acts as a pre-execution validator, not an executor. It checks for missing dependencies, circular references, resource conflicts, and ordering constraint violations. The output is a machine-readable report that your system can use to automatically reject invalid plans before they cause runtime failures, race conditions, or inconsistent state.

text
You are a pre-execution validation engine for tool call orchestration. Your job is to analyze a proposed execution plan and determine whether it is safe to execute. You do not execute any tools. You only validate the plan.

## INPUT
You will receive a proposed execution plan as a JSON object:

[EXECUTION_PLAN]

## VALIDATION RULES
Apply the following checks in order. Stop at the first violation unless [FAIL_FAST] is set to false.

1. **Missing Dependency Check**: For every tool call that declares a dependency on another tool call's output, verify that the referenced tool call exists in the plan and is scheduled to execute before the dependent call.
2. **Circular Dependency Check**: Traverse all dependency edges. If any cycle exists (A depends on B, B depends on A, or longer chains), flag it.
3. **Ordering Constraint Violation**: If the plan specifies a required execution order (e.g., sequential groups), verify that all dependency edges respect that order. A tool call must not depend on a tool scheduled to run after it.
4. **Resource Conflict Check**: If [RESOURCE_MAP] is provided, check whether any two tool calls in the same parallel group access the same mutable resource in conflicting ways (e.g., both writing to the same database row).
5. **Schema Compatibility Check**: For each dependency, verify that the output schema of the upstream tool contains the fields required by the downstream tool's input parameters.

## OUTPUT SCHEMA
Return a JSON object with the following structure:
{
  "plan_valid": boolean,
  "violations": [
    {
      "type": "missing_dependency" | "circular_dependency" | "ordering_violation" | "resource_conflict" | "schema_incompatibility",
      "severity": "blocking" | "warning",
      "description": "Human-readable explanation of the violation.",
      "offending_tool_calls": ["tool_call_id", ...],
      "dependency_chain": ["tool_call_id", ...] | null,
      "suggested_fix": "Actionable suggestion to resolve the violation."
    }
  ],
  "dependency_graph_summary": {
    "total_nodes": number,
    "total_edges": number,
    "parallel_groups": number,
    "sequential_chains": number,
    "max_chain_depth": number
  }
}

## CONSTRAINTS
- Do not hallucinate tool outputs. You are validating the plan structure only.
- If the plan is valid, return an empty violations array and set plan_valid to true.
- If [FAIL_FAST] is true, return only the first blocking violation found.
- If the input plan is malformed or unparseable, return a single violation of type "invalid_plan" with severity "blocking".

To adapt this template, replace the square-bracket placeholders with values from your orchestration context. [EXECUTION_PLAN] should be the full JSON object representing the proposed tool calls, their arguments, and their declared dependencies. [FAIL_FAST] controls whether the validator stops at the first error or collects all violations—set it to true for latency-sensitive pre-flight checks and false for plan debugging interfaces. [RESOURCE_MAP] is optional; provide it when your tools share mutable state like databases, caches, or file systems. If omitted, the resource conflict check is skipped. The output schema is designed for direct consumption by your plan executor's guard: if plan_valid is false, reject the plan and log the violations array for the developer. For high-risk production systems, always pair this prompt with a post-execution audit that compares actual tool call order against the validated plan.

IMPLEMENTATION TABLE

Prompt Variables

Placeholders required by the Tool Call Execution Plan Validation Prompt. Each variable must be populated before the prompt is sent to the model. Validation notes describe how to programmatically verify the input before injection.

PlaceholderPurposeExampleValidation Notes

[EXECUTION_PLAN]

The proposed list of tool calls, including tool names, arguments, and proposed execution order (parallel groups or sequential steps).

{"steps": [{"id": "call_1", "tool": "search_customer", "args": {"email": "[email protected]"}, "depends_on": []}, {"id": "call_2", "tool": "get_orders", "args": {"customer_id": "$call_1.id"}, "depends_on": ["call_1"]}]}

Must be valid JSON. Each step must have a unique id. depends_on must reference existing step ids. Parse and validate schema before injection.

[TOOL_REGISTRY]

A schema definition for every tool referenced in the execution plan, including parameter types, required fields, and side-effect classification (read/write).

[{"name": "get_orders", "parameters": {"customer_id": {"type": "string", "required": true}}, "side_effect": "read"}]

Must be a valid JSON array. Each tool must have a name and parameters map. Validate that every tool name in [EXECUTION_PLAN] has a corresponding entry here.

[RESOURCE_LOCKS]

A list of shared resources that tools may access, used to detect write-write or read-write conflicts.

["customer_db:write", "order_cache:read"]

Must be a JSON array of strings. Use resource:access_type format. If empty, pass an empty array. Null not allowed.

[CONSTRAINTS]

Operational constraints such as max parallel calls, timeout per call, and idempotency requirements.

{"max_parallel_calls": 5, "per_call_timeout_ms": 10000, "require_idempotency_keys": true}

Must be a valid JSON object. All numeric fields must be positive integers. Boolean fields must be true or false. Validate schema before injection.

[VALIDATION_RULES]

Custom business rules that the execution plan must satisfy, expressed as natural language assertions.

["call_1 must complete before call_2 because call_2 uses call_1 output as input", "No two write calls may target customer_db concurrently"]

Must be a JSON array of strings. Each string must be non-empty. If no custom rules exist, pass an empty array. Null not allowed.

[OUTPUT_SCHEMA]

The expected JSON schema for the validation report, defining the structure of pass/fail, violations, and error details.

{"type": "object", "properties": {"status": {"enum": ["pass", "fail"]}, "violations": {"type": "array"}}, "required": ["status", "violations"]}

Must be a valid JSON Schema object. Validate that it includes required fields for status and violations. Reject if schema is malformed.

[FAILURE_MODE_EXAMPLES]

Optional few-shot examples of invalid execution plans and their corresponding violation reports, used to calibrate the model's detection behavior.

[{"plan_fragment": "call_2 depends on call_1 but call_1 is not in plan", "expected_violation": {"type": "missing_dependency", "detail": "call_1 not found"}}]

If provided, must be a JSON array of objects with plan_fragment and expected_violation fields. If not used, pass an empty array. Null not allowed.

PROMPT PLAYBOOK

Implementation Harness Notes

How to wire the dependency validation prompt into a pre-execution guardrail with structured rejection, logging, and human review for high-risk plans.

This prompt is designed to operate as a synchronous pre-execution gate inside an agent orchestration engine. Before any tool call plan is dispatched to the runtime, the planner's proposed execution graph—including tool names, arguments, and declared dependency edges—is serialized into the [EXECUTION_PLAN] input. The model's structured output is parsed to extract the pass boolean and the violations array. If pass is false, the orchestration engine must block execution entirely and route the violation report to the calling service. Do not attempt to auto-correct the plan using this prompt; its job is validation, not repair. For repair, chain a separate recovery prompt that consumes the violation report and the original plan.

The harness should enforce a strict schema contract on the model's output. Use your inference platform's structured output mode (e.g., JSON mode with a supplied schema, function calling with strict: true) to guarantee that the response matches the expected { pass: boolean, violations: [...] } shape. Each violation object must include tool_call_id, violation_type (one of missing_dependency, circular_reference, resource_conflict, ordering_constraint), description, and severity (blocking or warning). If the model returns a malformed response or the schema validation fails, retry once with the same plan and a stronger instruction to output only the specified JSON. After a second failure, escalate the plan for human review rather than guessing. Log every validation result—pass or fail—with the plan hash, model version, and latency for audit and regression testing.

For high-risk domains where a false-negative validation could cause data corruption or unauthorized state changes, insert a human approval step when the plan contains any blocking severity violation or when the model's confidence appears low. The harness can detect low confidence by checking for ambiguous violation descriptions or by using a separate LLM-as-judge prompt that scores the validation quality. In regulated environments, store the full validation payload—including the input plan, the model's output, and the human reviewer's decision—as an immutable audit record. This prompt is a guardrail, not a planner; never use it to generate execution plans, only to reject invalid ones.

IMPLEMENTATION TABLE

Expected Output Contract

Validation rules for each field in the execution plan assessment output. Use these to build a post-processing validator that rejects malformed assessments before they reach the orchestration engine.

Field or ElementType or FormatRequiredValidation Rule

assessment.verdict

enum: PASS | FAIL

Must be exactly PASS or FAIL. Reject any other value.

assessment.plan_id

string matching ^plan-[a-f0-9]{8}$

Must match the [PLAN_ID] from the input. Reject if missing or mismatched.

violations

array of objects

Must be present. Empty array allowed only when verdict is PASS. Reject if null or missing when verdict is FAIL.

violations[].type

enum: MISSING_DEPENDENCY | CIRCULAR_REFERENCE | RESOURCE_CONFLICT | ORDERING_VIOLATION | UNKNOWN_TOOL

Must be one of the five enumerated values. Reject unknown violation types.

violations[].tool_call_id

string

Must reference a tool_call_id present in the input execution plan. Reject dangling references.

violations[].description

string, max 500 chars

Must be non-empty. Reject empty strings. Truncate to 500 characters in post-processing.

violations[].dependency_on

string | null

Required when type is MISSING_DEPENDENCY. Must reference a tool_call_id not present in the plan. Null allowed for other violation types.

violations[].cycle_path

array of strings | null

Required when type is CIRCULAR_REFERENCE. Must contain at least 2 tool_call_ids forming a cycle. Null allowed for other violation types.

PRACTICAL GUARDRAILS

Common Failure Modes

Tool call execution plans fail silently when dependencies are wrong. These are the most common failure modes in production dependency validation and how to prevent them before execution.

01

Circular Dependency Blind Spots

What to watch: The validation prompt misses circular dependencies when tools reference each other indirectly through intermediate outputs. Tool A requires Tool B's output, Tool B requires Tool C's output, and Tool C requires Tool A's output—forming a cycle that deadlocks execution. Guardrail: Require the prompt to perform full transitive closure analysis, not just direct pairwise checks. Include explicit cycle-detection instructions with a maximum depth parameter and flag any path where a tool depends on its own output, directly or indirectly.

02

Implicit Dependency Omission

What to watch: The model fails to detect dependencies that are semantically obvious but not syntactically declared. A tool that updates a user record depends on a prior read of that record, but if the dependency isn't in the schema, the validator marks the plan as valid. Guardrail: Include a pre-check step that infers resource-level dependencies from tool descriptions and parameter names. Require the prompt to flag any tool that mutates a resource without a corresponding read or creation step in the plan.

03

False Positive Ordering Constraints

What to watch: The validator enforces sequencing where parallel execution is safe, treating all same-resource tool calls as conflicting. This serializes independent operations and increases latency unnecessarily. Guardrail: Add explicit read-vs-write classification to the validation prompt. Read-after-read on the same resource is parallel-safe. Only enforce sequencing for write-after-read, read-after-write, and write-after-write conflicts. Include a parallel-safe override list for known idempotent operations.

04

Stale Dependency Reference After Plan Revision

What to watch: The execution plan is revised mid-flight due to a tool failure or timeout, but the dependency validation runs only once at plan creation. Subsequent tool additions or reorderings are never re-validated. Guardrail: Design the validation prompt to accept a diff or delta input, not just a full plan. Include instructions for incremental re-validation that checks only the changed dependency edges. Require a plan version identifier in the output so the execution engine can reject stale validations.

05

Resource Conflict Misclassification

What to watch: The validator treats all resource conflicts as blocking errors when some are benign. Two tools writing to different fields of the same object may be safe to parallelize, but the prompt flags them as a conflict and forces unnecessary sequencing. Guardrail: Add field-level granularity to the conflict detection rules. Require the prompt to distinguish between whole-resource conflicts and field-level conflicts. Include a severity classification: blocking (same field mutation), warning (same resource, different fields), and safe (read-only access).

06

Missing Timeout and Staleness Bounds

What to watch: The validation passes even when a dependency chain exceeds acceptable latency or when a read-after-write sequence has no staleness bound. The plan is structurally valid but operationally unsafe because data may be stale by the time it's consumed. Guardrail: Include time-bound constraints in the validation schema. Require the prompt to check that read-after-write steps include a maximum staleness threshold and that total dependency chain latency fits within the execution window. Flag any unbounded waits or missing timeout declarations.

IMPLEMENTATION TABLE

Evaluation Rubric

Use this rubric to test whether the Tool Call Execution Plan Validation Prompt correctly identifies dependency violations before integrating it into an automated rejection pipeline.

CriterionPass StandardFailure SignalTest Method

Missing dependency detection

Flags any tool call that consumes an output from a tool not present in the plan

Plan passes validation despite a tool requiring an output from a non-existent upstream call

Provide a plan where Tool B requires [TOOL_A_OUTPUT] but Tool A is omitted; assert validation fails with a missing-dependency error

Circular dependency detection

Identifies cycles where Tool A depends on Tool B and Tool B depends on Tool A

Plan passes validation despite a direct or indirect cycle in the dependency graph

Provide a plan with A->B and B->A; assert validation fails with a circular-reference error

Ordering constraint violation

Rejects plans where a tool is scheduled before its declared prerequisite

Plan passes despite Tool B executing before Tool A when B requires A's output

Provide a plan where execution order places Tool B before Tool A but B's schema declares [REQUIRES_OUTPUT_OF: Tool A]; assert ordering-violation error

Resource conflict detection

Flags two parallel tool calls that mutate the same resource without idempotency keys

Plan passes validation despite two concurrent write calls targeting the same resource with no isolation

Provide a plan with two parallel stateful-write calls to [RESOURCE_ID]; assert resource-conflict error

Partial dependency satisfaction

Rejects plans where a tool requires multiple upstream outputs but only a subset are provided

Plan passes despite Tool C requiring outputs from both Tool A and Tool B when only Tool A is present

Provide a plan where Tool C declares [REQUIRES_OUTPUT_OF: Tool A, Tool B] but only Tool A is scheduled; assert missing-dependency error for Tool B

Valid plan acceptance

Accepts a plan with correct dependency ordering, no cycles, and no resource conflicts

A correct plan is rejected with a false-positive error

Provide a valid plan with A->B->C and no shared mutable resources; assert pass with no violations

Structured error report format

Returns a parseable JSON error report with violation type, affected tools, and description

Error report is missing required fields, uses unstructured text, or omits affected tool identifiers

Trigger a missing-dependency violation; assert output contains valid JSON with fields: violation_type, tool_id, dependency_id, description

ADAPTATION OPTIONS

Adapt This Prompt

How to adapt

Add a structured tool registry input with declared input_fields, output_fields, side_effects, and resource_locks per tool. Feed this into the prompt as [TOOL_REGISTRY].

Include a [PREVIOUS_EXECUTION_STATE] placeholder for runtime context when validating mid-workflow plans. Add retry logic: if validation fails, return the error report to the planner model for correction before re-validation.

Watch for

  • Schema drift between the tool registry and actual tool implementations
  • Stale execution state causing false dependency violations
  • Validation latency adding unacceptable overhead to agent loops—consider caching validation results for repeated plan patterns
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.