The Agent Skills Directory

[EXTERNAL_DOWNLOADS]: Downloads and runs the firefox-devtools-mcp package from the npm registry via npx. This package is an official component from Mozilla.
[DYNAMIC_EXECUTION]: Employs the evaluate_script and evaluate_privileged_script tools to run arbitrary JavaScript in both the page context and the Firefox internal system context.
[PRIVILEGE_ESCALATION]: Supports a privileged context mode that enables the agent to access chrome-level contexts and modify browser preferences, which can bypass standard web-level restrictions.
[INDIRECT_PROMPT_INJECTION]: The skill ingests data from external websites, creating a surface where malicious content can manipulate agent instructions.
Ingestion points: Navigation and element inspection via navigate_page and take_snapshot (SKILL.md).
Boundary markers: The documentation warns about untrusted sites and recommends dedicated profiles, but lacks structured prompt isolation.
Capability inventory: Includes tools like script execution, file writing for screenshots, and network capture.
Sanitization: No specific filtering or escaping mechanisms for external web content are identified in the instructions.
[COMMAND_EXECUTION]: Uses npx to launch the MCP server and supports passing arbitrary Firefox binary paths and arguments through CLI flags.

firefox-devtools-mcp-automation