Google Postmaster Tools and Microsoft SNDS (Smart Network Data Services) expose reputation, spam-rate, authentication-pass-rate, and delivery-error data for a domain or IP directly from the mailbox provider's own perspective, rather than an estimate inferred from a sender's own logs.
This data is provider-specific and doesn't generalize; a domain can look healthy in Google Postmaster Tools while having problems specific to Microsoft or Yahoo that require checking each provider's own tooling separately.
These dashboards are typically the first place to check when inbox placement drops for a specific provider, since they show reputation and spam-rate trends the sender otherwise has no direct visibility into.