tailscale_create_user_inviteCreate a user invite to let someone join your tailnet. Assign a role such as member, admin, or auditor to control their access.
Create a new user invite that allows someone to join your tailnet.
| Name | Required | Description | Default |
|---|---|---|---|
| role | No | Role to assign to the invited user (default: member) | |
| No | Email address to send the invite to |
Changes observed during successful MCP inspections.
v0.19.1Input schema / properties / email / patternPrevious value: -"^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"New value: +"^(?:[A-Za-z0-9_'+\\-]+\\.)*[A-Za-z0-9_'+\\-]*[A-Za-z0-9_+-]@(?:[A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"v0.13.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, non-idempotent, openWorld, non-destructive, so the safety profile is covered. The description adds only that the invite lets someone join the tailnet; it omits whether an email is dispatched, invite expiry, rate limits, or required privileges. For a mutation that contacts an external party, that leaves meaningful gaps.
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?
A single short sentence, front-loaded with the verb and resource, with no filler. It is efficient, though borderline under-specified rather than maximally informative.
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 simple two-parameter creation tool with no output schema and annotations covering the safety profile, the description is minimally adequate. It nonetheless leaves out the delivery mechanism, invite lifecycle, and permission requirements that an agent would need to call this correctly.
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 coverage is 100% and the schema itself explains both the email target and the role enum with its default of 'member'. The description adds nothing about parameter behavior, so the baseline 3 for schema-complete tools applies.
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?
States a specific verb+resource ('Create a new user invite') with a brief note on its effect ('allows someone to join your tailnet'). However, it never distinguishes itself from the numerous sibling invite tools (tailscale_create_device_invite, resend_user_invite, list/get/delete_user_invite), so the agent must infer scope from the name alone.
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?
No when-to-use guidance, no prerequisites (e.g., admin role required, seat availability), and no mention of the alternatives such as device invites or resending an existing invite. An agent gets no routing help from this text.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.