Loading ToolBench
An interactive bench test launcher to evaluate MCP host support for MCP Apps
Scoring was not performed
Explicit discovery fixture: blob. Negative fixtures may fail to render. Precedence is a draft-profile check only.
Explicit discovery fixture: legacy. Negative fixtures may fail to render. Precedence is a draft-profile check only.
Explicit discovery fixture: malformed. Negative fixtures may fail to render. Precedence is a draft-profile check only.
Explicit discovery fixture: missing. Negative fixtures may fail to render. Precedence is a draft-profile check only.
Explicit discovery fixture: precedence. Negative fixtures may fail to render. Precedence is a draft-profile check only.
Explicit discovery fixture: text. Negative fixtures may fail to render. Precedence is a draft-profile check only.
Run draft MCP Apps audit probes. Results distinguish acknowledgement from verified host behavior.
Run stable MCP Apps audit probes. Results distinguish acknowledgement from verified host behavior.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-22 | F | 14 | 2025-06-18+ | v2 |
| 2026-03-09 | F | 23 | - | v1 |
Test display mode switching across the spec modes (inline, fullscreen, pip) and the bench extension modes (split-right, split-bottom, standalone)
Test inline and fullscreen display modes
Explicit inline-only declaration, separate from omitted display modes.
Test inline and pip display modes
Test undeclared display modes behavior
Inspect host context, capabilities, protocol version, and validate against the HostContext schema
Visualize host-provided CSS variables, typography, colors, shadows, and border radius tokens
Test media player capabilities for audio and video content
Test UI↔Host and UI↔Server messaging. Monitor requests, responses, and notifications
Inspect model context capabilities and message handling
Browser security probe with declared CSP/permissions. Permission probes run only on a user click.
Browser security probe with omitted CSP/permissions. Permission probes run only on a user click.
Inspect tool lifecycle events: input, partial input, results, and cancellation
Test transparency and opacity settings for UI rendering
Test tool visibility for model and app contexts
An interactive bench test launcher to evaluate MCP host support for MCP Apps