Daily Limits

A rule in MCP Guard can carry two limits on what an AI assistant does for a user in Microsoft Dynamics 365 Business Central in one day: a Daily Call Limit and a Daily Change Limit. The BC MCP Pro cloud connector applies them. The limits are a brake on an assistant that runs away, not a security boundary.

The two limits

Field	What it counts
Daily Call Limit	Every call of the AI assistant to Business Central for the user in one day, reading included.
Daily Change Limit	The calls that change, create or post something. Reading goes on when this limit is reached.

Three rules apply to both limits:

0 means no limit. The field is empty when the limit is 0.
On a line for a security group, the limit holds for each member on their own. The members do not share one limit.
The day is the UTC day.

Set a limit

Choose the search icon (Tell Me), enter MCP Guard User Settings, and then choose the related link.
On the line of the user or security group, enter a number in the Daily Call Limit field, the Daily Change Limit field, or both.

A negative number is refused. See Troubleshoot Rules and Licences.

You need the permission set MCP GUARD - ADMIN and an MCP Guard licence to change a rule.

Who applies the limits

Business Central does not see a tool call of an AI assistant, so the extension cannot count the calls itself. The extension stores the limits and reports them as dailyCallLimit and dailyChangeLimit on the mcpUserSettings API page. It also gives the signed-in user their own usage totals of the day, so that the connector's count starts where the day stands.

The limits need:

The BC MCP Pro cloud connector, version 0.13.0 or later.
Usage reporting switched on in that connector. See Usage per User.

The desktop connector does not apply the limits.

What happens at a limit

A call beyond a limit gets a fixed answer from the connector. The call is counted as Refused in the usage of the user. See Usage per User.

A brake, not a security boundary