Browser Setup
clacky-ai/openclacky
Configure the browser tool for Clacky. An agent skill from clacky-ai/openclacky.
Diagnose Firefox DevTools MCP setup issues. An agent skill from mozilla/firefox-devtools-mcp.
Custom licenceAuto-check passed
Install Firefox Devtools Diagnose
$ npx skills add mozilla/firefox-devtools-mcp --skill firefox-devtools-diagnose -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install mozilla/firefox-devtools-mcp firefox-devtools-diagnose --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/mozilla/firefox-devtools-mcp.git skills-src && mkdir -p .claude/skills && cp -r skills-src/plugins/firefox-devtools-troubleshoot/skills/diagnose .claude/skills/firefox-devtools-diagnose && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "firefox-devtools-diagnose" agent skill from https://github.com/mozilla/firefox-devtools-mcp/tree/main/plugins/firefox-devtools-troubleshoot/skills/diagnose into .claude/skills/firefox-devtools-diagnose/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "firefox-devtools-diagnose", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/mozilla/firefox-devtools-mcp/tree/main/plugins/firefox-devtools-troubleshoot/skills/diagnoseType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add mozilla/firefox-devtools-mcp --skill firefox-devtools-diagnose -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install mozilla/firefox-devtools-mcp firefox-devtools-diagnose --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mozilla/firefox-devtools-mcp.git skills-src && mkdir -p .agents/skills && cp -r skills-src/plugins/firefox-devtools-troubleshoot/skills/diagnose .agents/skills/firefox-devtools-diagnose && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "firefox-devtools-diagnose" agent skill from https://github.com/mozilla/firefox-devtools-mcp/tree/main/plugins/firefox-devtools-troubleshoot/skills/diagnose into .agents/skills/firefox-devtools-diagnose/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "firefox-devtools-diagnose", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add mozilla/firefox-devtools-mcp --skill firefox-devtools-diagnose -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install mozilla/firefox-devtools-mcp firefox-devtools-diagnose --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mozilla/firefox-devtools-mcp.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/plugins/firefox-devtools-troubleshoot/skills/diagnose .cursor/skills/firefox-devtools-diagnose && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "firefox-devtools-diagnose" agent skill from https://github.com/mozilla/firefox-devtools-mcp/tree/main/plugins/firefox-devtools-troubleshoot/skills/diagnose into .cursor/skills/firefox-devtools-diagnose/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "firefox-devtools-diagnose", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/mozilla/firefox-devtools-mcp.git --path plugins/firefox-devtools-troubleshoot/skills/diagnose--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add mozilla/firefox-devtools-mcp --skill firefox-devtools-diagnose -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install mozilla/firefox-devtools-mcp firefox-devtools-diagnose --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mozilla/firefox-devtools-mcp.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/plugins/firefox-devtools-troubleshoot/skills/diagnose .gemini/skills/firefox-devtools-diagnose && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "firefox-devtools-diagnose" agent skill from https://github.com/mozilla/firefox-devtools-mcp/tree/main/plugins/firefox-devtools-troubleshoot/skills/diagnose into .gemini/skills/firefox-devtools-diagnose/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "firefox-devtools-diagnose", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install mozilla/firefox-devtools-mcp firefox-devtools-diagnoseInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add mozilla/firefox-devtools-mcp --skill firefox-devtools-diagnose -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/mozilla/firefox-devtools-mcp.git skills-src && mkdir -p .github/skills && cp -r skills-src/plugins/firefox-devtools-troubleshoot/skills/diagnose .github/skills/firefox-devtools-diagnose && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "firefox-devtools-diagnose" agent skill from https://github.com/mozilla/firefox-devtools-mcp/tree/main/plugins/firefox-devtools-troubleshoot/skills/diagnose into .github/skills/firefox-devtools-diagnose/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "firefox-devtools-diagnose", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add mozilla/firefox-devtools-mcp --skill firefox-devtools-diagnose -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install mozilla/firefox-devtools-mcp firefox-devtools-diagnose --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mozilla/firefox-devtools-mcp.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/plugins/firefox-devtools-troubleshoot/skills/diagnose .opencode/skills/firefox-devtools-diagnose && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "firefox-devtools-diagnose" agent skill from https://github.com/mozilla/firefox-devtools-mcp/tree/main/plugins/firefox-devtools-troubleshoot/skills/diagnose into .opencode/skills/firefox-devtools-diagnose/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "firefox-devtools-diagnose", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
firefox-devtools-diagnose- GitHub stars
- 468
- Token cost
- ~672 tokens
- SKILL.md length
- 358 words
- Files
- 1
- Skills in repo
- 6
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Diagnose Firefox DevTools MCP setup issues. An agent skill from mozilla/firefox-devtools-mcp.
- Works in 4 steps: Check Node.js → Check Your Own Tool List → Check Installation and Tab Together → …
- Calls node
What it does
Firefox Devtools Diagnose is an agent skill from mozilla/firefox-devtools-mcp. Diagnose Firefox DevTools MCP setup issues. Activate when the firefox-devtools-mcp plugin fails to connect, its tools are not available, or the user reports Firefox DevTools not working in Cowork.
Its SKILL.md is about 670 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It works with Chrome DevTools, Node.js and Model Context Protocol. The repository describes itself as: Model Context Protocol server for Firefox DevTools - enables AI assistants to inspect and control Firefox browser through WebDriver BiDi.
Example prompts
- “/firefox-devtools-diagnose”
Requirements
- Node.js
Workflow steps
4 steps, taken from the step headings in SKILL.md.
- Check Node.js
- Check Your Own Tool List
- Check Installation and Tab Together
- Escalate
What it can do on your machine
Read from SKILL.md and the folder at commit 5c69888. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
node
From the folder's file list and the shell code blocks in SKILL.md.
Network
Links to these hosts (documentation or services it may open):
nodejs.orggithub.combugzilla.mozilla.orgchat.mozilla.org
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Firefox Devtools Diagnose loads about 672 tokens when it runs. Until then it costs about 56 tokens; SKILL.md has 358 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 358 words (~672 tokens).
“When Firefox DevTools MCP tools are unavailable or the user reports issues with the firefox-devtools-mcp plugin, run this diagnostic sequence automatically. Do not ask the user to do these checks manually.”
- name
- firefox-devtools-diagnose
Files
Just SKILL.md in plugins/firefox-devtools-troubleshoot/skills/diagnose of mozilla/firefox-devtools-mcp.
Open the folder on GitHubat commit 5c69888
Compare with similar skills
Firefox Devtools Diagnose next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Firefox Devtools Diagnose this skillmozilla/firefox-devtools-mcp | 468 | — | ~672 | Automated safety check: Pass | Custom licence | |
| Browser Setupclacky-ai/openclacky | 1.2k | — | ~3.1k | Automated safety check: Notes | MIT | |
| Nix Chrome Devtools MCPsrid/emanote | 963 | — | ~271 | Automated safety check: Pass | Custom licence | |
| Chrome CDP Browser Controlzenstory-ai/oh-story-claudecode | 7.3k | 2 repos | ~1.2k | Automated safety check: Pass | MIT | |
| Browser Testing with Chrome DevToolsaddyosmani/agent-skills | 102k | 4 repos | ~3.5k | Automated safety check: Warn | MIT | |
| agentmemory Setup and Diagnosticsrohitg00/agentmemory | 29k | — | ~1k | Automated safety check: Notes | Apache-2.0 |
Similar skills
Nix Chrome Devtools MCP
srid/emanote
chrome-devtools-mcp launcher — a single bash script that resolves Playwright's bundled Chrome-for-Testing and Node.js directly through Nix.
Chrome CDP Browser Control
zenstory-ai/oh-story-claudecode
Drives a Chrome window over the DevTools Protocol with the agent-browser CLI, so the agent can reuse your logged-in sessions, read pages and pull tokens.
Browser Testing with Chrome DevTools
addyosmani/agent-skills
Connects an agent to a real Chrome instance through the Chrome DevTools MCP server, so it can inspect the DOM, read console errors and profile performance directly.
agentmemory Setup and Diagnostics
rohitg00/agentmemory
Sets up and troubleshoots a local agentmemory install, covering the MCP connection, environment variables, ports, authentication and optional feature flags.
Stock API
zhangxiangliang/stock-api
Fetch real-time stock quotes, K-line (candlestick) history, and search symbols for China A-shares, Hong Kong, and US markets.
More from mozilla/firefox-devtools-mcp
Web Performance
mozilla/firefox-devtools-mcp
Find and fix why a website is slow by capturing and analyzing a Firefox performance profile, or by analyzing a profile the user already has (a saved file or a profiler.firefox.com share link).
Browser Automation
mozilla/firefox-devtools-mcp
This skill should be used when the user asks about browser automation, testing web pages, extracting content, filling forms, taking screenshots, or monitoring console/network activity.
Debug
mozilla/firefox-devtools-mcp
Show console errors and failed network requests. An agent skill from mozilla/firefox-devtools-mcp.
Navigate
mozilla/firefox-devtools-mcp
Navigate Firefox to a URL and take a DOM snapshot for interaction
Screenshot
mozilla/firefox-devtools-mcp
Take a screenshot of a URL or the current page. An agent skill from mozilla/firefox-devtools-mcp.
Related
Questions about Firefox Devtools Diagnose
What does Firefox Devtools Diagnose do?
Diagnose Firefox DevTools MCP setup issues. An agent skill from mozilla/firefox-devtools-mcp. Firefox Devtools Diagnose is an agent skill from mozilla/firefox-devtools-mcp. Diagnose Firefox DevTools MCP setup issues.
How do I install Firefox Devtools Diagnose in Claude Code?
Run `npx skills add mozilla/firefox-devtools-mcp --skill firefox-devtools-diagnose -a claude-code`. Or copy the skill folder (plugins/firefox-devtools-troubleshoot/skills/diagnose in mozilla/firefox-devtools-mcp) into .claude/skills/firefox-devtools-diagnose in your project. Claude Code loads it when a task matches its description.
How do I install Firefox Devtools Diagnose in Codex?
Run `npx skills add mozilla/firefox-devtools-mcp --skill firefox-devtools-diagnose -a codex`. Or copy the skill folder (plugins/firefox-devtools-troubleshoot/skills/diagnose in mozilla/firefox-devtools-mcp) into .agents/skills/firefox-devtools-diagnose in your project. Codex loads it when a task matches its description.
Can I use Firefox Devtools Diagnose in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mozilla/firefox-devtools-mcp --skill firefox-devtools-diagnose -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/firefox-devtools-diagnose, .gemini/skills/firefox-devtools-diagnose, .github/skills/firefox-devtools-diagnose and .opencode/skills/firefox-devtools-diagnose in your project.
What does Firefox Devtools Diagnose need to run?
Going by SKILL.md and its folder, Firefox Devtools Diagnose needs the command-line tools its instructions call (node). Our summary lists: Node.js.
Does Firefox Devtools Diagnose access the network?
SKILL.md names 4 domains. As links in the text: nodejs.org, github.com, bugzilla.mozilla.org and chat.mozilla.org. This is read from the text; nothing was executed.
Is Firefox Devtools Diagnose safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Firefox Devtools Diagnose use?
Firefox Devtools Diagnose has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.
How many tokens does Firefox Devtools Diagnose use?
About 672 tokens (SKILL.md is roughly 2.7k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Firefox Devtools Diagnose?
Skills that share tags, products or a category with Firefox Devtools Diagnose: Browser Setup (clacky-ai/openclacky, 1.2k stars), Nix Chrome Devtools MCP (srid/emanote, 963 stars), Chrome CDP Browser Control (zenstory-ai/oh-story-claudecode, 7.3k stars) and Browser Testing with Chrome DevTools (addyosmani/agent-skills, 102k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Firefox Devtools Diagnose?
mozilla (a GitHub organization) maintains it in mozilla/firefox-devtools-mcp, which has 468 GitHub stars. The repository holds 6 skills in this directory. The repository was last updated on October 6, 2026.
Source: mozilla/firefox-devtools-mcp on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.