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

Beyond the annotations, it discloses acting on behalf of the account owner, the 20-per-hour limit, the absence of push notifications, the need to poll later, and the requirement to show the user the text before sending. This is substantial behavioral context that annotations alone do not provide.

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 dense but every sentence carries operational value: action, identity, parameter selection, rate limit, polling behavior, and user confirmation. The ANTWORTEN/ERSTEN contrast provides clear scannable structure without fluff.

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?

Given the three-parameter tool with no output schema, the description covers the full workflow: how to choose and source parameters, what happens on first contact (chat is created), the rate limit, and what to do after sending. Nothing needed for correct invocation is missing.

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?

Although schema coverage is 100%, the description adds crucial semantics: chat_id is for an existing conversation, post_id is for first contact, and exactly one must be provided. It also tells the agent where each ID comes from, which the schema does not convey.

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 opens with a specific verb and resource: 'Schreibt im Marktplatz-Chat von Open Platform.' It clearly differentiates this marketplace-chat write operation from sibling read tools like nachrichten_lesen and chats_ansehen, and clarifies it is not a private inbox.

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 explicit when-to-use guidance: use chat_id when replying in an existing chat and post_id for first contact, with exact source tools for each. 'Genau eines von beidem' enforces exclusivity, and the preference for benachrichtigungen over chats_ansehen is a practical selector.

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