add_sending_domainRegister a domain the user owns for outbound demand-test sends. Returns DNS records (SPF, DKIM, MX) to add at the DNS provider. After DNS propagates, call verify_sending_domain. Cannot be a shiply.now subdomain.
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | e.g. mail.yourbrand.com |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
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?
The annotations declare openWorldHint=true and idempotentHint=true, and the description adds meaningful behavioral context: the tool returns DNS records (SPF, DKIM, MX) and requires subsequent verification. It does not contradict any 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?
The description is concise with three well-structured sentences. The first sentence immediately states the primary purpose, and subsequent sentences provide necessary details without redundancy.
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 simple single-parameter tool with an output schema (implied), the description covers all essential aspects: purpose, required resource, return type, follow-up action, and a constraint. It is fully adequate for the tool's complexity.
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 input schema has 100% description coverage for its only parameter 'domain', with an example ('e.g. mail.yourbrand.com'). The description does not add additional semantics beyond the schema, so a baseline score of 3 is 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 clearly states the action ('Register a domain'), resource ('the user owns'), and purpose ('for outbound demand-test sends'). It also specifies that DNS records will be returned and the next step (call verify_sending_domain). This effectively distinguishes it from sibling tools like add_custom_domain or add_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 provides clear usage context: it registers a domain for sending and requires DNS propagation and verification. It also explicitly states a constraint ('Cannot be a shiply.now subdomain'). However, it does not mention when not to use this tool or direct alternatives, so a slight deduction.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.