Create organization tailnet

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

The description goes well beyond the annotations by disclosing that the response contains a one-time OAuth client secret, that MCP clients may persist responses, that creation requires specific credentials, that there is a 10-tailnet limit, and that duplicate-name behavior is ambiguous between alreadyExists and a 400. This is exactly the kind of behavioral context an agent needs and is not inferable from annotations or schema.

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?

Although the description is longer than typical, every section earns its place: the core purpose and return value are front-loaded, followed by security, auth, quota, and duplicate-handling guidance. The formatting with labeled sections makes it scannable despite the density of information.

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?

For a create operation with unusual security and idempotency implications and no output schema, the description is remarkably complete. It covers return values, secret sensitivity, credential prerequisites, quota limits, and ambiguous failure modes, leaving an agent well-equipped to call the tool correctly and handle results appropriately.

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%, and both parameters (displayName and organization) already have descriptive text including uniqueness and default behavior. The description adds no additional parameter-level details beyond what the schema provides, so the 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 opens with a specific action and resource: 'Create a new API-only tailnet in your organization.' It also clarifies what is returned (the tailnet plus an OAuth client), which distinguishes it from sibling create operations like create_oauth_app or create_webhook. The purpose is unambiguous and not a tautology.

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 clear context for when to use the tool: it requires an OAuth client with the 'tailnets' scope, explains that an API key will not work, and describes follow-up actions after creation. It also tells the agent to call tailscale_list_org_tailnets before retrying after a timeout. It does not explicitly enumerate when not to use it, but for a create operation this is reasonable context.

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