douyin_login_qrcode

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

With only a title annotation, the description carries the behavioral burden well: it discloses that a browser is launched, that the login state persists in the browser profile across all subsequent tools, and that the return value is a local image path. It does not cover failure modes such as timeout or what happens if a session already exists.

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?

Short and front-loaded: the action and return value come first, followed by the persistence side effect and the user instruction. Every sentence carries information, with only minor redundancy around the waiting instruction.

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 login tool with no output schema, the description covers the action, the returned artifact, and the persistent side effect that matters most to an agent planning later calls. It leaves out the precondition of checking existing login status and the timeout outcome, which keeps it from a 5.

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%, including the waitSeconds default and the 0=no-wait case, so the schema already does the heavy lifting. The description's 'wait during scanning' wording adds modest context but no formatting or edge-case detail beyond the schema.

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: opens a browser and fetches the creator-center login QR code, returning a local image path. That distinguishes it from douyin_login_status and douyin_logout by implication, though it never names those siblings explicitly.

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 intended context is clear: run this when a login is needed, have the user scan with the Douyin App, and afterwards all other tools work without logging in again. It gives no explicit when-not guidance (e.g. 'check douyin_login_status first if already logged in'), so it falls short of a 5.

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