# Tool Call Contract Mismatch

## Ontology Metadata

Code: ISS-0017
Version: ISS-0017@0.1.0
Ontology release: 0.1.0
Updated: 2026-05-10T00:00:00Z
Canonical URL: /workbench/issues/tool-call-contract-mismatch/

## Summary

The AI or agent calls a tool with names, arguments, types, modes, or shapes that do not match the declared tool interface.

## Category

- CAT-0040 — MCP, Tools & Integrations
  - URL: /workbench/categories/mcp-tools-and-integrations/
  - Summary: Problems involving tool calls, MCP surfaces, integration contracts, required tool inputs, tool results, parser consumers, or downstream systems that depend on AI output.

## Primary Pattern

- PAT-0150 — Interface Mismatch
  - URL: /workbench/patterns/interface-mismatch/
  - Summary: A structural condition where observed interface behavior, shape, or exchange differs from the declared interface contract.

## Declared Patterns

- PAT-0150 — Interface Mismatch
  - URL: /workbench/patterns/interface-mismatch/
  - Summary: A structural condition where observed interface behavior, shape, or exchange differs from the declared interface contract.
- PAT-0160 — Schema Breakage
  - URL: /workbench/patterns/schema-breakage/
  - Summary: A structural condition where an instance, graph, payload, or object violates the type, shape, or rule requirements of a declared schema.
- PAT-0180 — Compatibility Violation
  - URL: /workbench/patterns/compatibility-violation/
  - Summary: A structural condition where a graph, object, behavior, or runtime state exceeds a declared compatibility envelope without an authorized exception.

## Derived Primary Lenses

- LEN-0130 — Compatibility Envelope Lens
  - URL: /workbench/lenses/compatibility-envelope-lens/
  - Summary: Determines whether structure fits within declared runtime, platform, version, or support constraints.
- LEN-0200 — Interface Contract Lens
  - URL: /workbench/lenses/interface-contract-lens/
  - Summary: Compares declared interface structure to observed runtime structure to detect contract deviations.
- LEN-0210 — Invariant Lens
  - URL: /workbench/lenses/invariant-lens/
  - Summary: Verifies that declared invariants are structurally enforceable and not contradicted by observed structure.

## Derived Secondary Lenses

- LEN-0120 — Boundary Compliance Lens
  - URL: /workbench/lenses/boundary-compliance-lens/
  - Summary: Evaluates observed structure against declared boundary posture, including allow, block, and exception rules.
- LEN-0150 — Conflict Lens
  - URL: /workbench/lenses/conflict-lens/
  - Summary: Detects mutually incompatible constraints, claims, states, or declarations that cannot be simultaneously satisfied.
- LEN-0230 — Normalization Lens
  - URL: /workbench/lenses/normalization-lens/
  - Summary: Transforms structurally equivalent variants into a canonical form to prevent false divergence.

## Search Intents

- AI tool call wrong arguments
- tool call contract mismatch
- function call invalid arguments
- AI called tool with wrong schema
- agent used wrong tool parameters
- tool choice is underspecified