Set a provider credential

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate it is a write (not read-only) and not idempotent. The description adds valuable behavior: it snapshots the previous state and explicitly points to nuvio_undo for reverting, which is not inferable from the annotations. This gives the agent a clear picture of the operation's mutability and reversibility.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, dense sentence that front-loads the core purpose and immediately gives the provider enumeration. The snapshot/revert note is concise and placed after the primary action, making it easy to parse without clutter. Every word earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a credential-setting tool with no output schema, the description covers the essential operational aspects: what providers are accepted, the key type distinction, and the undo path. The profile_id parameter is left to the schema, which is acceptable given its default and bounds. The description does not mention success/error behavior, but that is minor for a simple write operation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema describes api_key and provider with brief text, but the description enriches the provider parameter by listing exact accepted values (debrid:torbox, tmdb, etc.) and distinguishes that animeskip requires a client id rather than an API key. This compensates for the lack of an enum and adds meaning beyond the schema. profile_id is not mentioned, but its schema includes default and range, so the 67% coverage is partially mitigated.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('Store') and a specific resource ('an API key for a provider'), and enumerates the allowed providers, which makes the purpose unambiguous. It clearly differentiates from siblings by implying a write operation (store) versus list/delete, so an agent can distinguish it from nuvio_list_provider_credentials and nuvio_delete_provider_credential.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives no guidance on when to use this tool versus alternatives like nuvio_delete_provider_credential or nuvio_list_provider_credentials. It mentions revert with nuvio_undo, but that is about recovery, not about choosing the tool. There is no explicit context like 'use this to set a new credential' or 'use delete to remove'.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.