Before You File a Bug Report Please Confirm You Have Done The Following...

• I have tried restarting my IDE and the issue persists.
• I have updated to the latest version of the packages.
• I have searched for related issues and found none that matched my issue.
• I have read the FAQ and my problem is not listed.

Playground Link

https://typescript-eslint.io/play/#ts=5.9.2&fileType=.ts&code=JYOwLgpgTgZghgYwgAgLIE8CiUoHsrIQAekIAJgM7LZ4EDeyAvgFDNkQIA2cUKCuICmEI58ALjRZRUANzNotAHRhcAZTBRQAcwAUAShlA&eslintrc=N4KABGBEBOCuA2BTAzpAXGUEKQAIBcBPABxQGNoBLY-AWhXkoDt8B6Jge1oCMBDZRLXxdk%2BKkwDm6MAG1w2HImjQO0SABp5CrAuyRKEztEQATAColEAOV4BbFNLm7dkAKLLVkLboC63iAC%2B3n6BIAFAA&tsconfig=N4KABGBEDGD2C2AHAlgGwKYCcDyiAuysAdgM6QBcYoEEkJemy0eAcgK6qoDCAFutAGsylBm3TgwAXxCSgA&tokens=false

Repro Code

interface MyError extends Error { }

declare const error: MyError;
error.toString();

ESLint Config

{
  "rules": {
    "@typescript-eslint/no-base-to-string": [
      "error",
      {
        "ignoredTypeNames": [
          "Error"
        ]
      }
    ]
  }
}

tsconfig

{
  "compilerOptions": {
    "strictNullChecks": true
  }
}

Expected Result

There should be no lints.

Actual Result

'error' will use Object's default stringification format ('[object Object]') when stringified. 4:1 - 4:6

Additional Info

There is some discussion in #11420