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

Annotations already mark this as non-read-only, non-idempotent, and non-destructive. The description adds that it starts an interactive browser flow, requires human entry of the userCode, requires OSIR credentials, and depends on a follow-up call. It omits details like token expiry or whether concurrent device sessions are allowed, but it significantly enriches the behavioral profile.

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?

Four short sentences, front-loaded with the action and output names, then the user steps and follow-up call in order. Every sentence earns its place and there is no filler.

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 zero-parameter tool with no output schema, it covers the initiation purpose, key returned values, the human actions, and the next call. It is slightly incomplete because 'deviceCode' is only referred to as 'returned' without being explicitly listed among return values, and no expiration/lifetime behavior is mentioned.

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 tool has zero parameters, and the empty schema already covers the parameter surface. The description confirms this explicitly with 'No parameters required,' which is all that is needed; there is no undocumented parameter burden.

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 precise action ('Start a device authorization login'), cites RFC 8628, and names the outputs (verificationUri, userCode) and the follow-up call. This clearly distinguishes it from siblings like checkDeviceLoginStatus as the initiation step.

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?

It gives an explicit trigger condition and a direct next step ('Then call checkDeviceLoginStatus with the returned deviceCode'), so the agent knows when to use it and how to complete the flow. It does not list negative alternatives such as loginToVpsPanel, but the workflow context is clear.

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