create_contactAdd new contacts to SendGrid with email, names, and custom fields. Build your audience for email campaigns by importing multiple contacts at once.
Create new contacts in your SendGrid account
| Name | Required | Description | Default |
|---|---|---|---|
| contacts | Yes | Array of contact objects |
Changes observed during successful MCP inspections.
v1.1.1Input schema / additionalPropertiesRemoved value: -falseInput schema / properties / contacts / items / additionalPropertiesRemoved value: -falseInput schema / properties / contacts / items / properties / custom_fields / propertyNamesAdded value: +{
+ "type": "string"
+}v1.0.0Input schema / $schemaAdded value: +"http://json-schema.org/draft-07/schema#"Input schema / additionalPropertiesAdded value: +falseDoes the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this is a write operation (readOnlyHint=false) and non-destructive (destructiveHint=false). The description adds no additional behavioral context, such as how duplicates are handled, whether existing contacts are updated, or any rate limits. The idempotentHint=true suggests repeated calls with the same email may not duplicate, but the description doesn't clarify this behavior, which could be important for an agent deciding how to invoke it.
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 a single, concise sentence with no redundant words or filler. It immediately states the action and object, making it easy for an agent to parse.
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 simplicity, a single-parameter schema, and annotations that cover safety and idempotency, the description is minimally viable. However, it lacks any mention of related tools, expected outcomes, or behavioral nuances, so an agent has no guidance beyond the raw definition and schema.
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%, with every parameter and nested property described in the input schema itself. The description adds no parameter-level detail, so with fully self-documenting schema, the baseline 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 'Create new contacts in your SendGrid account' clearly states the verb (create), the resource (contacts), and the scope (SendGrid account). It is unambiguous about what the tool does, though it doesn't explicitly differentiate itself from the sibling create_contact_with_lists, which is a neighboring variation.
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 gives no guidance on when to use this tool versus alternatives such as create_contact_with_lists or update_contact. There is no mention of prerequisites, complementary tools, or exclusions, so an agent would have to infer usage context from the name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.