扫码登录：生成二维码

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

Annotations declare readOnlyHint=false and openWorldHint=true, so the description's added value is the interactive flow: this tool starts a session that only completes after a human scans and confirms, and a follow-up call is required. It does not mention QR expiry/timeout, behavior if already logged in, or whether repeated calls invalidate prior codes — real gaps for a stateful auth flow, but the core behavior is disclosed.

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?

Three compact sentences: what it does, how to present the result, what to call next. Front-loaded action verb, zero filler, every clause carries operational instructions.

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?

With no parameters and no output schema, the description usefully names the return payload (an image or qr_text) and the required follow-up call, which is exactly what the agent needs to drive the flow. Missing only failure/expiry handling and the already-authenticated case.

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?

Zero parameters, so there is nothing to disambiguate and the baseline is 4. The description does not waste words on inputs, correctly focusing on the interaction protocol instead.

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 and resource (生成网易云音乐登录二维码) and implicitly distinguishes itself from the sibling login_qr_check by framing this tool as the generator and that one as the poller. An agent can tell these two apart without opening either schema.

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?

Explicit sequencing: show the QR to the user (image or qr_text in a code block), have them scan and confirm in the app, then call login_qr_check. That names the exact next tool and the human-in-the-loop condition, leaving nothing to inference.

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