A search route and a listener deletion job do not need the same authority. Giving both the widest available key makes configuration simple at first, but it expands the effect of a mistake or exposed credential.
Start with a list of actual operations. For each one, note the documented endpoint, required scope, environment, and service that performs it.
Use a small permission map
A catalog-only service may need read access without listener writes. A backend that mints listener tokens needs a different capability. Administrative or destructive operations deserve a clearly controlled path rather than accidental access through a generic API proxy.
Use scope names from the current provider contract. Similar words in another provider's API are not evidence that the same permission exists here. Keep your deployment configuration close to the reviewed map so it can be checked during changes.
Separate credentials by service where the provider and your operating model support it. This can make rotation and investigation easier. Balance that benefit against the extra secret-management work rather than creating many unused keys.
Prove the limits
A permissions test should include a request that is expected to fail. For example, a read-only test caller should not be able to change listener data. A successful search alone does not prove that a key is safely limited.
Record the failure category without exposing the credential. If a new feature needs another scope, make that an explicit configuration change with a reason.
The goal is a permission set that matches the service's job. Smaller authority does not replace input validation or account checks, but it gives those controls a more useful boundary when something goes wrong.