Articles · Gemini AI Tools
Combine Gemini’s built-in tools, not a shell on App Service
An agent box is easy to treat as an autonomous operator that can reach your disk and your LAN. It is not. Gemini Agent Playground attaches only Gemini built-in tools that this host already exposes elsewhere: Google Search (paid, 5/hour), URL context for a validated public URL, code execution at Google, File Search for uploaded documents, and structured JSON output. Unknown tool names are dropped. There is no shell, process start, or arbitrary HTTP fetch from DevNestro. Retrieved page or file text is treated as data, not as instructions that can change credentials or the allow-list.
Why this is worth doing in the browser
People want an agent playground because mixing Search with a JSON answer is faster than three separate pages. Shipping a generic “call any URL” agent would recreate SSRF and command-execution bugs. This page stays inside the capability matrix. Free-tier Search fails closed. Localhost URLs fail closed. File Search without a file fails closed. Related tools include function calling for a display-only custom schema and web research when you only need grounding. Results are drafts. Verify sources.
How to use the tool
Write a prompt. Check the built-in tools you need. Add a public URL for URL context or documents for File Search. Confirm cloud processing. Run agent. Read the draft and any sources. Clear drops the session files and text.
- Do not upload confidential files unless you accept Google processing.
- Google Search requires a paid host and shares the Search rate limit.
- Code execution runs at Google, not on DevNestro.
- This is not a general computer-use agent and not Remote MCP.
Privacy
The prompt and any selected public URL or files are sent to Google Gemini with the tools you allowed. Temporary File Search stores are deleted after the request. DevNestro does not run generated shell commands. This is not processed only in your browser. Free-tier training language follows the configured tier.
Have a prompt you are willing to send with built-in tools? Open Gemini Agent Playground, expect paid Search to refuse on a free host, and read the result as a draft.