hetzner_change_primary_ip_rdnsChange the reverse DNS (PTR) record for a Hetzner Cloud primary IP, or set dns_ptr to null to reset it.
Change the reverse DNS entry for a primary IP. Set dns_ptr to null to reset.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Primary IP ID | |
| ip | Yes | IP address to set the reverse DNS entry for | |
| dns_ptr | Yes | Reverse DNS PTR record value, or null to reset |
Changes observed during successful MCP inspections.
v3.0.0Input schema / properties / dns_ptr / anyOfRemoved value: -[
- {
- "type": "string"
- },
- {
- "type": "null"
- }
-]Input schema / properties / dns_ptr / typeAdded value: +[
+ "string",
+ "null"
+]v2.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false and openWorldHint=true, covering the safety/idempotency profile. The description adds one genuinely useful behavioral detail — passing null clears the PTR record — but says nothing about permissions, propagation/delay, or what happens to the pre-existing record beyond the reset hint.
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 short sentences, zero filler, and the core action is front-loaded before the reset caveat. Appropriate size for a simple mutation tool.
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 existing annotations, a fully documented 3-parameter schema, and no output schema, the description is adequate to invoke the tool correctly. It falls short only on sibling disambiguation (three other change-*_dns/rdns tools exist) and on failure/permission context.
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%; the schema already documents id, ip, and dns_ptr, including 'or null to reset'. The description's null-reset sentence is therefore a restatement rather than added meaning, 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 (change) and resource (reverse DNS entry for a primary IP), which is clear on its own. However, the sibling list contains near-identical tools (hetzner_change_dns_ptr, hetzner_change_floating_ip_rdns, hetzner_change_lb_dns_ptr), and the description never explicitly contrasts itself against them beyond the 'primary IP' scope phrase.
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, no prerequisites (e.g. IP must be assigned), and no routing away from the sibling rdns/dns_ptr tools. The only actionable hint is the reset condition, which is a how-to rather than a usage guideline.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.