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

Adds critical context the annotations do not: billing begins per-hour on boot, the exact parameter driving cost (server type), and where to learn prices. It also surfaces the credential consequence of omitting ssh_keys (root password emailed), which is genuinely operationally important for a provisioning call.

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 tight sentences with the highest-stakes fact (billing starts) front-loaded in caps, followed by prerequisites and the API endpoint. Nothing is wasted or buried.

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?

Covers the preconditions, cost implications and credential behaviour needed to invoke it correctly. The only gap is the lack of any hint about the returned resource (e.g. a server object plus an action), which matters since there is no output schema; otherwise it is complete.

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 name, image, server_type, labels, location, ssh_keys, user_data and start_after_create are all self-documented including defaults and examples. The description adds no parameter-level detail beyond what the schema already provides, so the baseline 3 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?

States a specific verb and resource ('Provision a new server') that no sibling shares, and names the underlying API call. An agent can immediately distinguish this from power/reboot/backup siblings.

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 directs the agent to call hetzner_list_server_types first for prices and hetzner_list_images for a bootable image, which is strong prerequisite routing. It does not state when *not* to use it or contrast with a sibling create-path, but the preconditions are clear.

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