Interoperability

Agent Tool is a normalization and linking layer. It should not swallow the native protocol.

MCP

Preserve tools/list, tools/call, tool name, title, description, inputSchema, outputSchema, annotations, structuredContent, content, isError, _meta, resource_link, and embedded resources. Add Agent Tool ids and policy/evidence/runtime refs around them.

OpenAPI

Preserve operationId, method, path, server, security schemes, request schemas, and response schemas. Add agent-specific surfaces, invocation lifecycle, and result mapping.

Function calling APIs

Preserve provider tool_call_id, function name, tool choice, strictness, deferred loading flags, and parallel-call semantics. Add portable invocation ids and policy/evidence refs.

A2A

Preserve Agent Card, AgentSkill id, task id, context id, message id, and artifact id. Agent Tool can describe a peer agent capability as a tool without replacing the peer protocol.

CLI and local tools

Preserve command id, argv, working directory, environment policy, sandbox ref, timeout, signal, exit code, stdout/stderr refs, and background task id.

Telemetry

Preserve trace id, span id, GenAI tool call attributes, native request ids, duration, decision source, and result-size fields. Do not store sensitive arguments or results in telemetry unless explicitly enabled and redacted.