A fine-grained PAT restricted to product-api provides an enforceable repository-level authorization boundary for agent1. GitHub fine-grained personal access tokens can be limited to selected repositories and assigned only the repository permissions required by the workload. Consequently, even if agent1 attempts to access billing-service or infra-terraform, the credential does not authorize access to those repositories. GitHub specifically recommends fine-grained PATs when repository access must be restricted to particular repositories.

This directly aligns with the GH-600 objective to configure an agent ' s scope to a specific repository and define execution boundaries through repository context and permissions. Microsoft Learn defines execution context as including the repository an agent can access and emphasizes that repository scope is the first boundary limiting agent behavior.

Option A provides behavioral guidance but is not a security authorization boundary. Option B controls the permissions available to the workflow token but does not, by itself, establish the required cross-repository credential restriction. Option D only prevents certain push operations; it does not stop agent1 from reading or otherwise accessing the other repositories.

Study Guide Reference Topics: Implement Tool Use and Environment Interaction → execution context and boundaries; repository-specific agent scope; tool permissions; least-privilege authentication.