ts_expire_device

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

No annotations are provided, so the description must carry full burden. It states 'Force key expiry' implying a destructive mutation, but does not disclose side effects, required permissions beyond the env var, or whether the action is reversible. Minimal behavioral context.

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?

Two sentences, no wasted words. The first sentence states the purpose, the second adds a critical requirement. Front-loaded and efficient.

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 (one required param, output schema exists), the description covers purpose, prerequisite, and parameter. It is sufficiently complete for an agent to understand and invoke the tool 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 description coverage is 100% (device_id is described as 'Device nodeId (from ts_devices)'), so baseline is 3. The tool description does not add extra meaning beyond the schema for the parameter; it only restates the prerequisite.

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 clearly states the verb 'Force key expiry' and the resource 'device', and the clarification 'it must re-authenticate' adds specificity. This differentiates it from sibling tools like ts_delete_device (deletion) or ts_authorize_device (authorization).

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 mentions a prerequisite (TAILSCALE_WRITE_ENABLED=true) but does not provide explicit guidance on when to use this tool versus alternatives like ts_delete_device or ts_authorize_device. No exclusions or alternative recommendations are given.

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