Pre-PEP alignment

toolschema intentionally mirrors the May 2026 Pre-PEP proposal for inspect.tool_schema() and @typing.tool.

Proposed stdlib	toolschema equivalent
inspect.tool_schema(fn) -> dict	schema(fn).to_json_schema()
@typing.tool	@tool
tool.validate(args)	schema(fn).validate(args)
JSON Schema 2020-12 canonical	ToolDefinition.parameters uses draft 2020-12
Annotated metadata	Field(...) and plain-string Annotated descriptions

Standard Schema interop (v1.0+)

toolschema also implements the Standard Schema and Standard JSON Schema protocols so ecosystem tools can consume tool schemas without custom adapters:

from toolschema import schema, JSONSchemaOptions
import fixtures

tool = schema(fixtures.add)
standard = tool.standard["~standard"]

assert standard["version"] == 1
assert standard["vendor"] == "toolschema"

input_schema = standard["jsonSchema"]["input"](JSONSchemaOptions(target="draft-2020-12"))
result = standard["validate"]({"a": 2})
assert result.value == {"a": 2, "b": 1}

When/if CPython ships inspect.tool_schema, this package can become a thin compatibility wrapper or serve as the reference test suite.