Mail-Server einer Adresse ermitteln

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

Annotations already declare readOnlyHint and openWorldHint. The description adds meaningful behavioral context: it does not log in, requires no password, and does not connect to the mailbox. This goes beyond the annotations and reassures the agent about safety and network usage.

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?

Three concise sentences, front-loaded with the primary purpose, followed by usage context and a safety note. No redundant or extraneous content.

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 read-only detection tool with no output schema, the description covers the essential behavioral aspects: what it does, when to use it, and that it's non-invasive. It could mention the return format (e.g., structured settings), but that's a minor gap given the tool's simplicity.

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 covers 100% of parameters with descriptions for both 'email' and 'online'. The description does not add any parameter-specific information beyond what the schema provides, so the baseline of 3 is appropriate.

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 clearly states the verb 'Ermittelt' (determines) and the resource: IMAP/SMTP settings for an email address. This is specific and immediately distinguishes it from sibling tools, which all perform mailbox operations (move, search, send, etc.) rather than provider detection.

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 provides explicit context on when to use the tool: when the user doesn't know their provider or when automatic detection failed. It doesn't explicitly name alternatives or exclusions, but the sibling list makes it obvious this is the only detection tool, so the guidance is clear.

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