cloud_create_firewallDefine firewall rules and apply them to Hetzner Cloud resources to control inbound and outbound traffic. Specify name, direction, protocol, port, and source or destination IPs.
Create a firewall with rules. Free.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | Firewall name. | |
| rules | No | Rule objects: direction, protocol, port, source_ips or destination_ips. | |
| apply_to | No | Resources to apply the firewall to on creation. |
Changes observed during successful MCP inspections.
v0.7.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It only adds that rules are included and that the operation is free; it does not disclose permissions, immediate effect, reversibility, or what happens when apply_to is omitted.
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 extremely short and front-loaded, with no wasted wording. However, the terse 'Free.' fragment is useful but not structurally integrated into a fuller sentence that would earn a 5.
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 mutation tool with no annotations and no output schema, the description is too minimal. It does not explain required vs optional parameters, default behavior for rules or apply_to, or any operational side effects the agent needs to call it safely.
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 description coverage is 100%, so the schema itself documents name, rules, and apply_to. The description adds 'with rules' but no syntax, defaults, or constraints beyond what the schema already provides, making the baseline of 3 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 states a specific verb and resource: 'Create a firewall with rules.' This is clear and directly distinguishes the action from sibling list/delete operations, but it does not differentiate from other create tools such as cloud_create_network beyond the resource name.
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?
No when-to-use guidance, prerequisites, or alternatives are provided. 'Free' is a pricing note rather than usage context, leaving the agent to infer when this tool is appropriate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.