Complete reference for Material 3 Expressive (M3E) — Google's design system GA on Android 16 (Sep 2025). Covers: MaterialExpressiveTheme setup, MotionScheme, new components (ButtonGroup, FloatingToolbar, DockedToolbar, LoadingIndicator, SplitButtonLayout, FABMenu), MaterialShapes + shape morphing...
Part of the AndroJack MCP MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents call material3_expressive to retrieve information from AndroJack MCP without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though material3_expressive only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
tools:
material3_expressive:
rules:
- action: allowSee the full AndroJack MCP policy for all 22 tools.
Agents calling read-class tools like material3_expressive have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Read risk category across the catalogue. The same policy patterns (rate-limit, allow) apply to each.
Complete reference for Material 3 Expressive (M3E) — Google's design system GA on Android 16 (Sep 2025). Covers: MaterialExpressiveTheme setup, MotionScheme, new components (ButtonGroup, FloatingToolbar, DockedToolbar, LoadingIndicator, SplitButtonLayout, FABMenu), MaterialShapes + shape morphing, variable font typography, Wear OS M3E, migration from plain M3, and anti-patterns. Call this before building any Compose UI or theming. Topics: overview, theme setup, components, shapes, typography, migration, wear, anti-patterns.. It is categorised as a Read tool in the AndroJack MCP MCP Server, which means it retrieves data without modifying state.
Add a rule in your Intercept YAML policy under the tools section for material3_expressive. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the AndroJack MCP MCP server.
material3_expressive is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the material3_expressive rule in your Intercept policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the Intercept policy for material3_expressive. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
material3_expressive is provided by the AndroJack MCP MCP server (androjack-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Open source. One binary. Zero dependencies.
npx -y @policylayer/intercept