AI Agent Spec Builder
Build a clear specification for an AI agent covering its goals, tools, guardrails and behavior before you build it, free in your browser.
Agent spec
Your prompt
Copy-ready prompt
A template built from your inputs — paste it into your AI tool. Runs in your browser; nothing is uploaded.
How to use this calculator
- State the agent's goal and list the tools/APIs it can use.
- Add constraints and success criteria.
- Copy the prompt to generate the agent's planning spec.
How it works
The prompt asks for a deterministic, safe plan — the agent's role, a step-by-step sequence with the tool used at each step, guardrails and failure handling, and how to verify success — and to ask for missing info rather than assume.
It builds the planning prompt; it does not run an agent or write code.
Common mistakes
- Leaving the agent's tools and limits undefined — vague specs lead to unpredictable behaviour.
- Omitting guardrails; always state what the agent must not do.
Frequently asked questions
Does this use AI or send my prompt anywhere?
No. It runs entirely in your browser using rule-based checks — your prompt is never uploaded or sent to any AI model. Still, avoid pasting passwords, API keys or private data into any tool.
What is an agent spec?
A clear description of an AI agent's goal, tools, inputs, outputs and guardrails. The tool assembles your choices into a spec prompt or document.
Does it build the agent?
No — it produces the specification you'd hand to a developer or paste into an agent framework; nothing is run or uploaded here.
Related tools
- Claude Code Prompt Builder
- AI Business Idea Prompt Builder
- AI Data Analysis Prompt Builder
- AI Structured Output / JSON Prompt Builder
- AI Token & Cost Estimator
- AI Citation Requirements Prompt Builder
Explore more in AI Tools.
Cite this tool
Zerdly. (2026). AI Agent Spec Builder. Retrieved from https://www.zerdly.com/tools/ai-agent-spec-builder/
Tip: Enter any known values to calculate the remaining results.
Designed to run locally in your browser. Tool inputs are not intentionally stored by Zerdly unless stated otherwise.