Module tools 

Tool trait, registry and the shapes handlers return. Handlers get a RequestContext and return structured results; the protocol layer turns them into MCP results.

Re-exports

pub use error::ToolError;

pub use error::ToolErrorCode;

pub use handler::Tool;

pub use handler::ToolHandler;

pub use handler::ToolRegistry;

Modules

args

Tool arguments. Their JSON Schemas are the tools’ input schemas; keep field docs short, every schema must stay well under the clients’ size limits.

catalog

Every tool’s name, description, annotations and scope. The input schema comes from the handler’s arguments.

error 🔒

The errors tools return, and how each reaches the agent.

handler 🔒

The tool handler trait and the registry dispatch looks tools up in.

schema

Input schema generation: draft 2020-12, no oneOf/anyOf and no nullable type arrays, so the schemas survive Codex’s schema sanitiser.

Structs

ConfirmationRequest

A human decision the handler needs before it can finish, such as confirming a risky publish.

McpPrincipal

Who an MCP request acts for, from a validated access token.

RequestContext

Everything a handler knows about the request besides its arguments.

RetryState

Echoed state of a confirmation round trip, already verified.

ToolResult

A structured tool result. Hints live inside the structured object because clients drop the text content when structured content is present.

Enums

McpScope

A capability an MCP token can carry.

ToolOutcome

How a handler call ended.

Constants

CONFIRMATION_KEY 🔒

Key of the confirmation in the input requests and responses.

Functions

off_worker 🔒

Runs CPU-heavy pure work, such as an engine pass over every page, on the blocking pool, so that the worker thread keeps serving other requests meanwhile.