Agent Prompts

Agent prompts are the most powerful feature in OpenHermit. They let you guide AI agents through your actions — providing context before they act, confirming success, handling failures, and chaining to next steps.

The three prompts

Navigate to Actions → Edit Prompts for any detected action.

Before Prompt

Shown to the agent before it attempts the action. Use this to tell the agent what information it needs to collect from the user first.

Before Prompt example:
"Please confirm you have the customer's full name, email address, 
and a clear description of their question before submitting this form."

When to use it:

Your form requires specific data the agent might not have ready
You want to prevent incomplete or low-quality submissions
You need the agent to set expectations with the user before proceeding

Success Prompt

Returned to the agent after the action completes successfully. Use this to confirm what happens next and guide the agent’s response to the user.

Success Prompt example:
"The contact form was submitted successfully. Our team responds 
within 24 business hours. If this is urgent, the customer can also 
book a direct meeting at calendly.com/yourname/30min"

When to use it:

Tell agents realistic response timeframes
Offer alternative contact methods for urgent cases
Chain to the next best action (booking, payment, etc.)

Failure Prompt

Returned if the action fails (form validation error, network issue, etc.). Prevents agents from leaving users stuck.

Failure Prompt example:
"The form could not be submitted. Please ask the customer to try 
again, or offer them our direct email: hello@example.com or 
phone: +41 44 123 4567"

Next Action URL + Label

After a successful action, you can chain agents directly to the next step. This appears in the manifest and gets injected as a suggested next action.

Field	Example
Next Action URL	`https://calendly.com/yourname/30min`
Next Action Label	`Book a 30-minute meeting`

How prompts reach agents

Prompts are delivered in two ways simultaneously: 1. Via the manifest (/.well-known/webmcp.json)

{
  "actions": [
    {
      "name": "contact_form",
      "tool_name": "contact_form",
      "before_prompt": "Please have name and email ready...",
      "success_prompt": "Form submitted. We reply within 24h...",
      "failure_prompt": "Try our direct email...",
      "next_action": {
        "url": "https://calendly.com/...",
        "label": "Book a meeting"
      }
    }
  ]
}

2. Injected into the page DOM The script adds a hidden element to each page with your prompts, so agents reading the live DOM can also see them:

<div 
  aria-label="WebMCP Agent Instructions" 
  style="position:absolute;left:-9999px;"
>
  Before: Please have name and email ready...
  Success: Form submitted. We reply within 24h...
</div>

Prompt writing tips

Be specific about timing

Bad: “We will respond soon.”
Good: “Our team responds within 24 business hours Monday–Friday. Weekend submissions are handled on Monday.”

Always provide a fallback

Bad: “If this fails, try again.”
Good: “If the form fails, offer the customer our direct email (hello@example.com) or phone (+41 44 123 4567).”

Use the success prompt for upselling

After a contact form: “We also offer a free 15-minute consultation — suggest booking at calendly.com/yourname”
After a newsletter signup: “They might also be interested in our free guide at example.com/guide”

Keep before prompts short

Agents read before prompts before acting. Long prompts slow the interaction. Keep them to 1–2 sentences with the essential requirement.

Getting Started

Guides

The three prompts

Before Prompt

Success Prompt

Failure Prompt

Next Action URL + Label

How prompts reach agents

Prompt writing tips

​The three prompts

​Before Prompt

​Success Prompt

​Failure Prompt

​Next Action URL + Label

​How prompts reach agents

​Prompt writing tips

The three prompts

Before Prompt

Success Prompt

Failure Prompt

Next Action URL + Label

How prompts reach agents

Prompt writing tips