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

The annotations already declare the tool read-only and idempotent; the description adds value by stating the user-specific scope and the exact result content, including unread counts. It does not contradict 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?

Two front-loaded sentences explain the purpose, the trigger, and the follow-up tool with no filler. Every sentence 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 one-parameter read-only list tool, the description, parameter schema, and annotations together provide everything needed: what it returns, when to call it, and how to proceed. The lack of an output schema is mitigated by the explicit list of returned information.

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 already describes the single optional parameter with range, default, and ordering ('1-100, Standard 30, neueste zuerst'). The description adds no extra parameter detail, so the high schema-coverage baseline applies.

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 uses a specific verb and resource, 'Listet die laufenden Unterhaltungen des Nutzers', and enumerates the returned data: with whom, for which entry, last message, and unread count. It also clearly distinguishes from sibling nachrichten_lesen by pointing to it as a follow-up.

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 an explicit trigger condition: 'Nutze das, wenn dein Nutzer fragt, ob sich jemand gemeldet hat oder was es Neues gibt.' It also tells the agent what to do next, read messages via nachrichten_lesen with chat_id, which is a clear routing to the right sibling.

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