Edit tool rules | Agenetix Docs

Tool rules let you control exactly how an AI agent interacts with each tool. Instead of relying on the raw OpenAPI description, Agenetix gives you structured fields that compose into the instructions the AI sees.

Available rule fields#

Field	Purpose	Example
Description override	Replace the OpenAPI description entirely	"Creates a new todo item in the authenticated user's list"
Instructions	General guidance for the AI when using this tool	"Always confirm the item title with the user before creating"
When to use	Selection guidance — when to pick this tool	"When the user wants to add a new task or todo item"
When not to use	Avoidance guidance — when NOT to pick this tool	"When the user is asking about existing items or browsing"
Examples	Example invocations as JSON	`[{"input": {"title": "Buy groceries"}}]`

How rules work#

When an agent considers using a tool, it sees a composed description built from your rule fields:

MERMAID

flowchart TD
    Override["Your description override"] --> |"takes priority"| Base["Base description"]
    Source["OpenAPI description"] --> |"used if no override"| Base
    Base --> Final["What the AI sees"]
    Inst["Instructions"] --> Final
    WTU["When to use"] --> Final
    WNTU["When not to use"] --> Final
    Ex["Examples"] --> Final

The AI sees something like:

PLAINTEXT

Creates a new todo item in the authenticated user's list
 
[Instructions]
Always confirm the item title with the user before creating
 
[When to use]
When the user wants to add a new task or todo item
 
[When NOT to use]
When the user is asking about existing items or browsing

Editing rules in the dashboard#

Open the MCP server detail page.
Go to the Tools tab.
Click any tool to expand its rule editor.
Fill in the fields you want to customize — all fields are optional.
Save your changes.

You only need to fill in what matters for your use case. If an AI is picking the wrong tool, adding when to use and when not to use guidance is usually the most effective fix.

Rules survive OpenAPI refresh#

When you refresh the OpenAPI spec, Agenetix merges changes without losing your work:

Your description override, instructions, when to use, when not to use, and examples are never overwritten by a refresh
Only the original OpenAPI-derived description and input schema update from the new spec
The enabled/disabled state of each tool is preserved

See OpenAPI refresh & merge for the full merge behavior.