PAT-0150
Interface Mismatch
A structural condition where observed interface behavior, shape, or exchange differs from the declared interface contract.
Primary Lenses
Interface Contract Lens
Compares declared interface structure to observed runtime structure to detect contract deviations.
Lens Application
The Interface Contract Lens is a primary inspection mechanism for Interface Mismatch because it aligns declared interface expectations with observed runtime evidence. It helps surface where inputs, outputs, schemas, methods, timing, or exchange patterns diverge from the stated contract without treating the mismatch as already resolved.
Inspect For
- Declared fields, types, or methods missing at runtime
- Runtime payloads that differ from documented schemas
- Version, protocol, or endpoint behavior drift
- Error patterns caused by incompatible assumptions
Avoid
Treat a detected deviation as an inspection signal rather than conclusive evidence without checking context, versioning, adapters, or intentional contract evolution.
Secondary Lenses
Normalization Lens
Transforms structurally equivalent variants into a canonical form to prevent false divergence.
Lens Application
As a secondary lens, the Normalization Lens helps inspect Interface Mismatch indirectly by canonicalizing equivalent payload shapes, naming variants, formats, or ordering differences before comparison. This can make residual mismatch signals easier to see without treating every variation as contract divergence.
Inspect For
- Equivalent fields expressed with different names, casing, or order
- Format differences that normalize to the same value
- Payload variants that collapse into one canonical structure
- Residual differences after normalization
Avoid
Treat normalized equivalence as a signal for comparison, not confirmation that the interface fully matches its declared contract.
Primary Issue Matches
Supporting Issue Matches
Agent Cannot Choose Tool Without Tool Result
The agent needs a tool result to choose the right tool, but cannot obtain that result without choosing a tool first.
Agent Gets Conflicting Tool Authority
An agent receives conflicting authority signals about whether, when, or how it may use a tool, connector, function, or integration.
AI Output Breaks Parser
The AI output causes a parser, validator, importer, or structured-output consumer to fail.
Citation Points to Wrong Source
A citation, reference, link, or source pointer is present, but it points to the wrong source, wrong passage, wrong document, or unsupported evidence.
Invalid JSON Output
The AI returns malformed JSON or structured output that cannot be parsed.
Model and Workflow Disagree on Next Step
The AI model recommends or selects a next step that conflicts with the workflow state, required handoff, routing rule, or process sequence.
Nested Fields Do Not Match
The AI returns nested structured fields whose internal shape, hierarchy, parent-child relationship, or contained values do not match the expected structure.
Output Breaks the Next Step
The AI output looks acceptable by itself but cannot be used by the next tool, workflow step, parser, reviewer, or downstream consumer.
Prompt Changed but Workflow Did Not
A prompt changes but the workflow, parser, review step, routing rule, or downstream expectation still assumes the old prompt behavior.
Same Contract Name Has Different Meanings
The same prompt, schema, field, policy, tool, or workflow contract name is used in different places with different meanings.
Tool Can Act Without Responsible Authority
A tool, connector, function, or integration can perform an action without a declared responsible authority for that action.
Tool Exists but Required Inputs Are Missing
A usable tool or integration exists, but the AI or agent does not have the required inputs, permissions, fields, identifiers, or context needed to call it correctly.
Tool Result Not Integrated Correctly
The AI receives a tool result but misreads, ignores, overwrites, misplaces, or fails to incorporate it correctly into the final output or workflow state.
Tool Rules and Prompt Rules Conflict
Tool, connector, function, or MCP rules conflict with prompt instructions, causing the AI or agent to face incompatible requirements.
Wrong Field Types
The AI returns fields with values whose types do not match the expected schema, such as strings where numbers, booleans, arrays, objects, or enums are required.