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

Adds substantial context beyond the readOnly/openWorld/idempotent annotations: 10-hour access token, 30-day refresh token, the response being returned only once and needing immediate storage, and the fact that unauthenticated sessions see only public tools. None of this is recoverable from the annotations.

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?

Front-loaded with the core action and dense with useful constraints, but the refresh_access_token instruction is repeated twice (once as 'don't log in again' and again as the grant_type=refresh_token note), which is avoidable redundancy in an otherwise efficient block.

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?

With no output schema, the description correctly describes the return payload (access_token + refresh_token) and their lifetimes, plus prerequisites (register first) and credentials semantics. An agent has everything needed to call and follow up 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 coverage is 100% and the schema already documents client_id as username/email and client_secret as password/secret, so the description's parenthetical glosses are pure duplication with no added syntax, format, or constraint detail. Baseline 3 applies when the schema does all the work.

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?

States a specific verb and resource ('Ein Bearer-Token holen' – exchange credentials for tokens) and immediately frames it as the entry point. It distinguishes itself from sibling auth tools by naming refresh_access_token and register explicitly, so an agent can differentiate without opening other schemas.

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?

Gives explicit when-to-use (once at the beginning), when-not (do NOT log in again; use refresh_access_token, which needs no password), and named alternatives for adjacent cases (register for no account, web UI for forgotten password). Routing is unambiguous.

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