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

Beyond annotations, it discloses rate limiting ('Hoechstens 20 pro Stunde'), absence of push notifications with polling guidance, acting under the account holder's name, and the marketplace-versus-private-inbox distinction. These are exactly the behavioral details an agent needs before sending.

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 purpose and identity constraint are front-loaded, followed by clear reply/first-contact branches, rate limit, polling behavior, and user-confirmation guidance. It is dense but every sentence provides operational value.

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 non-idempotent, open-world send tool with no output schema, the description covers identity, rate limit, no-push polling, parameter branching, and user confirmation. Nothing essential 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?

Schema coverage is 100%, so the baseline is 3, but the description adds the critical mutual-exclusivity rule and workflow meaning for chat_id versus post_id. It does repeat some schema text, but the 'bevorzugt' note and chat-creation consequence add real value.

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 action ('Schreibt im Marktplatz-Chat') and scope ('Marktplatz-Kontakt, kein privater Posteingang'). It distinguishes reply versus first-contact behavior and names relevant sibling tools, so an agent can identify it without opening the schema.

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?

Explicitly says to use chat_id for replies from chats_ansehen or benachrichtigungen, and post_id for first contact from markt_ansehen or meine_treffer. It also states 'Genau eines von beidem', describes polling after send, and instructs showing text to the user before sending.

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