sync_dnsFor a connected custom domain, (re)write the CNAME records for all its subdomains automatically and report what changed. For unconnected domains, returns the records to add manually.
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | registered custom domain to sync, e.g. example.com |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
Input schema / properties / domain / descriptionAdded value: +"registered custom domain to sync, e.g. example.com"Output schema / (root)Previous value: -nullNew value: +{
+ "$schema": "http://json-schema.org/draft-07/schema#",
+ "additionalProperties": false,
+ "properties": {
+ "result": {}
+ },
+ "required": [
+ "result"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond annotations (idempotentHint, openWorldHint), the description reveals that syncing modifies DNS records automatically and reports changes, and that for unconnected domains it behaves as a read-only guide. This adds useful behavioral context without contradicting annotations.
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 concise sentences. The first covers the primary automated action, the second covers the alternative manual case. No extraneous words, every sentence earns its place.
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 tool's moderate complexity, the description adequately explains both operational modes. With an output schema present, it does not need to detail return format. The two sentences cover the essential scenarios.
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?
The only parameter 'domain' is sufficiently described in the schema. The description adds value by explaining how the domain's connection status affects behavior, providing additional semantic context beyond the basic schema.
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?
Description clearly states the tool syncs DNS records for connected custom domains by automatically rewriting CNAME records and reporting changes, while for unconnected domains it returns manual instructions. This specific verb+resource+scope distinguishes it from siblings like add_custom_domain or check_custom_domain.
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?
The description explains two distinct use cases (connected vs unconnected domains) and implies when to use the tool for automated sync vs manual guidance. While it doesn't explicitly list alternatives, the context is sufficient for an agent to decide.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.