feat(unstable): add tool call name

[benbrandt]

No description provided.

[Copilot]

Pull request overview

This PR introduces an unstable optional name field on tool call objects (ACP v1 and v2) to carry the programmatic identifier of the invoked tool, enabling clients to display “which tool” was used in addition to the existing human-readable title and categorical kind.

Changes:

• Extend the unstable JSON schemas (v1/v2) and generated protocol docs to include ToolCall.name.
• Implement name in the Rust schema crate behind unstable_tool_call_name, including v1↔v2 conversion behavior and tests (preserving v2 patch semantics, and erroring on v2 name: null when converting to v1).
• Add an RFD (“Tool Call Name”), link it into docs navigation, and record the lifecycle update entry.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
schema/v2/schema.unstable.json	Adds optional nullable name to v2 tool-call update schema with patch semantics.
schema/v1/schema.unstable.json	Adds optional nullable name to v1 tool-call and tool-call-update schemas (null/omission semantics).
docs/rfds/updates.mdx	Records the RFD moving to Draft stage.
docs/rfds/tool-call-name.mdx	New RFD describing motivation, wire semantics, and compatibility notes.
docs/protocol/v2/draft/tool-calls.mdx	Documents name field and adds it to the example tool-call update.
docs/protocol/v2/draft/schema.mdx	Adds generated schema docs entries for name in relevant v2 shapes.
docs/protocol/v1/draft/tool-calls.mdx	Documents name field and its update semantics; updates example tool call.
docs/protocol/v1/draft/schema.mdx	Adds generated schema docs entries for name in relevant v1 shapes.
docs/docs.json	Adds the new RFD page to the docs navigation.
agent-client-protocol-schema/src/v2/tool_call.rs	Adds ToolCallUpdate.name as a three-state patch field behind a feature flag, plus patch semantics tests.
agent-client-protocol-schema/src/v2/conversion.rs	Adds v1↔v2 conversion for name, including a v2→v1 null-unrepresentable error test.
agent-client-protocol-schema/src/v1/tool_call.rs	Adds optional ToolCall.name and ToolCallUpdateFields.name behind a feature flag, plus serialization/update tests.
agent-client-protocol-schema/Cargo.toml	Introduces unstable_tool_call_name feature and includes it in the unstable umbrella.