sparkpost-mcp

create_subaccount

Create a subaccount and provision an API key with defined permissions for email sending and account management.

Instructions

Create a subaccount with an API key (name, key_label, key_grants)

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "name": "<name>",
      "key_label": "<key_label>",
      "key_grants": "<key_grants>"
    },
    "name": "create_subaccount"
  }
}

Input Schema

Name	Required	Description	Default
`name`	Yes
`key_label`	Yes
`key_grants`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Jul 8, 2026

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It only states the creation action without mentioning side effects, authentication needs, idempotency, or error handling. The description adds minimal behavioral insight beyond the basic operation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single concise sentence with no extraneous information. It is front-loaded with the action. However, the brevity sacrifices completeness in other dimensions, earning a slight deduction.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has 3 required parameters, no output schema, and no annotations, the description is insufficient. It lacks information about return values, side effects, error conditions, and whether creation is idempotent. An agent would lack critical context to use this tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The description enumerates the three parameter names but adds no semantic meaning or constraints beyond what the input schema provides. Since schema description coverage is 0%, the description should compensate, but it fails to explain the purpose or format of each parameter (e.g., name rules, key_label usage, key_grants allowed values are already in schema).

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Create a subaccount with an API key') and lists the required parameters (name, key_label, key_grants). It effectively distinguishes this tool from sibling tools like list_subaccounts or create_webhook, as it specifies creating a subaccount with an API key.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites, conditions, or exclusions, such as when to use list_subaccounts instead. The lack of usage context makes it hard for an agent to decide 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.