tailscale_expire_deviceExpire a device's key to force re-authentication. Provide the device ID to invalidate its current session and require a fresh login.
Expire a device's key, forcing it to re-authenticate.
| Name | Required | Description | Default |
|---|---|---|---|
| deviceId | Yes | The device ID to expire. nodeId from tailscale_list_devices (e.g. nPM2KNuedB21DEVEL); numeric id ok; not the nodeKey. |
Changes observed during successful MCP inspections.
v0.21.0Input schema / properties / deviceId / descriptionPrevious value: -"The device ID to expire"New value: +"The device ID to expire. nodeId from tailscale_list_devices (e.g. nPM2KNuedB21DEVEL); numeric id ok; not the nodeKey."v0.13.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already mark the tool as destructive and idempotent; the description adds the key consequence that the device must re-authenticate, which clarifies the real-world effect of the action. It does not cover immediate availability or permissions, but given annotation coverage this is adequate.
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?
One short sentence ('Expire a device's key, forcing it to re-authenticate.') delivers the essential action and consequence with zero padding. This is ideal for a one-parameter tool.
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 single-parameter destructive action with a fully self-documenting schema and safety annotations, the description plus schema provides sufficient information for correct invocation. It does not mention preconditions like admin rights, but that is a minor gap for a tool this simple.
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?
The single parameter deviceId is fully documented in the schema with an example and an explicit warning against using nodeKey. The description text adds no additional parameter semantics, so it relies entirely on the schema, matching the baseline for 100% coverage.
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 states a specific verb ('Expire'), a resource ('a device's key'), and the effect ('forcing it to re-authenticate'). This clearly distinguishes it from siblings like tailscale_delete_device or tailscale_update_device_key.
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 provides no guidance on when to use this tool versus alternatives such as tailscale_update_device_key or tailscale_deauthorize_device. It only states what the tool does, leaving the selection decision entirely to the agent.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.