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

Beyond the annotations, the description discloses the critical side effect of token rotation: the new refresh_token replaces the old one. It also documents the passwordless flow, the 10-hour expiry, and the exact response fields, which are important behavioral details for an agent to invoke it correctly.

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 front-loaded with the core purpose and then adds rotation, expiry, and return-shape details. It is efficient overall, though the trailing English keyword line ('refresh, access, token') is not essential for an agent deciding how to call the tool.

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 simple one-parameter tool with no output schema, the description is complete: it explains what the tool does, when to use it, the passwordless requirement, the rotation behavior, and the returned fields. An agent has enough information to invoke it correctly.

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?

Schema description coverage is 100%, and the single parameter is already fully documented in the schema. The description reiterates that the refresh_token is valid and comes from login or a previous refresh, but adds no syntax, format, or validation detail beyond the schema.

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 OAuth2 operation: exchanging a valid refresh_token for a new access_token plus a rotated refresh_token. It clearly distinguishes the action from password-based login by emphasizing 'OHNE Passwort' and naming the token exchange explicitly.

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?

It gives a clear usage condition: refresh proactively before expiration, with expires_in=10h noted. It also implies this is the alternative to password login by saying no password is needed, but it does not explicitly name sibling tools such as login or auth_status.

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