OCI MCP Server

create_subnet

Create a subnet in OCI by specifying compartment, VCN, CIDR block, and display name. Supports regional subnets by omitting availability domain.

Instructions

Create a subnet. Omit availability_domain for a regional subnet.

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": {
      "compartment_id": "<compartment_id>",
      "vcn_id": "<vcn_id>",
      "display_name": "<display_name>",
      "cidr_block": "<cidr_block>"
    },
    "name": "create_subnet"
  }
}

Input Schema

Name	Required	Description	Default
`compartment_id`	Yes
`vcn_id`	Yes
`display_name`	Yes
`cidr_block`	Yes
`availability_domain`	No
`security_list_ids`	No
`route_table_id`	No
`dns_label`	No
`prohibit_public_ip`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0May 30, 2026

TDQS

C2.9/5.0

Behavior2/5

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

No annotations are provided, so the description must disclose behavior. It only says 'Create a subnet,' implying a mutating operation, but lacks details on permissions, side effects, or state changes (e.g., whether creation is idempotent or what errors occur if the subnet already exists).

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 extremely concise (one sentence plus a hint) and front-loaded. While it wastes no words, the brevity may sacrifice important context. It earns a 4 for efficiency but loses a point for under-specification given the tool's complexity.

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 9 required and optional parameters, no output schema, and no schema descriptions, the description is insufficient. It covers only the availability_domain nuance, leaving agents to guess the roles of cidr_block, security_list_ids, route_table_id, dns_label, and prohibit_public_ip.

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?

With 0% schema description coverage and 9 parameters, the description only adds meaning for 'availability_domain' ('omit for regional subnet'). The other 8 parameters (compartment_id, vcn_id, cidr_block, etc.) are left unexplained, forcing the agent to rely solely on parameter names.

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 'Create a subnet' with a specific verb and resource, and the additional hint about omitting availability_domain for a regional subnet differentiates this from other sibling tools like create_vcn or create_security_list, which serve different purposes.

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 only usage guidance is 'Omit availability_domain for a regional subnet,' which is a parameter-specific hint. There is no comparison to alternatives or explanation of when to use this tool over other related tools like create_internet_gateway or create_nat_gateway.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server