Oktasays identity-scoped Model Context Protocol (MCP) tool lists can reduce AI agent token costs.
Each model call made by an AI agent can include schemas, names, descriptions and parameters for every tool exposed by a MCP server. Okta calls the resulting prompt overhead the “tool tax”: tokens consumed as a model considers tools, including those it will never call.
The company argues that this cost appears before an agent attempts a tool call. A later rejection of an unauthorised request therefore cannot recover prompt tokens already consumed. Okta’s proposed control filters the list of tools before it reaches the model, using permissions assigned to an agent identity and the user associated with it.
Okta’s internal modelling found that some permission scenarios reduced the number of visible tools by more than 90%. The company said tool-schema costs fell by roughly the same proportion, although it did not provide absolute token or dollar figures.
MCP servers have become a route for connecting AI agents to tools and data. Okta cites connections to Google Workspace, Slack and internal MCP servers as examples. An MCP server can expose a large number of tools, and the model receives a representation of each available tool in its prompt on every turn.
That representation includes a schema. It also includes the tool name, description and parameters.
Okta says the cost compounds when a widely used MCP server exposes many tools. Each active user incurs the prompt overhead whenever their agent makes a model call. The company frames this as both a tool-count problem and a user-count problem.
The issue also has an access-control dimension. An agent that sees tools outside its authorisation scope can attempt to use them. A control that rejects the call at runtime can block execution, though the model has already received the tool definition and used tokens to process it.
Okta positions the capability within its “blueprint for the secure agentic enterprise”, which asks organisations to identify their agents, their permitted connections and their authorised actions.
Its approach narrows the connection question from access to a whole MCP server to access to individual tools on that server. An administrator configures the tools that a particular identity may use in the Okta dashboard. Okta then returns the scoped tool set instead of the server’s full catalogue.
The agent receives this shorter list in its prompt for each turn. Okta says it checks scope again at runtime before a tool call executes.
This design applies least-privilege access at the tool level. The company says an agent should not be aware of resources, databases or tools that it has not been expressly authorised to use. Removing unavailable tools from the prompt also removes their schema cost from the model call.