MCP and API keys

When a connection or a tool fails

What the common MCP errors mean and what to do about each one.

The connection itself

What you seeWhat it meansWhat to do
The client asks you to sign in againThe credential is missing, revoked or expiredRe authorise. Repeating the same request won't help.
Everything is refused after a whileThe MCP session expiredReconnect, then pick the brand again.
Requests start failing in burstsRate limited for this credentialWait the time the error names, then try the same thing again.

Refusals before anything ran

Nothing changed when you see these.

Message namesMeaningWhat to do
Access or scopeThe connection doesn't carry the access the tool needsGrant it in API Keys, or use a connection that has it.
No brand is activeNothing brand specific can run yetAsk the assistant to list your brands and pick one.
Your planYour Koast plan doesn't include that toolChange plan, or do it in the app.
This ad accountThe brand's ad provider doesn't support itA brand on a different provider may.
Publish limitThere's no publish limit, or the launch would exceed itSet or raise the limit. Nothing was published.
ConfirmationThe client couldn't ask you to confirm, or you declinedNothing was published. Try from a client that can prompt.

Refusals from the tool

Message namesMeaningWhat to do
Not foundThe id doesn't exist under this brand or batchAsk the assistant to re list and try again.
Permission or roleYour role doesn't carry itAn organization admin has to grant it.
Changed since you read itSomething moved underneathRe read and retry.
More than one ad accountThe request was ambiguousName the account.
Read only right nowThe surface can't writeSwitch out of a read only mode or connection.

One retry, then stop

If a refusal is about access, plan or provider support, it will fail the same way every time. Retrying burns your rate limit and tells you nothing new.

Nothing here matches

Contact Koast support with the message the assistant showed you, word for word, and roughly when it happened.

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