Secrets manager

The values an agent's tools read at run time, write-only: once saved, only a hint comes back. Secrets a tool needs and nobody has set are listed first, each with one field, so a missing key is found here and not in a failed run. Paste a .env block to add several at once, replace or remove one in place, and keep a value per environment. Reads what a tool set needs from each AI SDK tool's contextSchema.