login_qr_start

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

With no annotations provided, the description carries full behavioral disclosure burden. It richly describes the output (image block, terminal QR, file path, stderr), the 2-minute expiry, and the app scanning step, which is far more than typical. It does not detail error conditions or session lifecycle side effects, but it covers the essential behavior well.

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?

The description is lengthy but highly structured with numbered points, front-loading the core purpose and then detailing the various output formats. Each sentence earns its place, and the structure aids readability. It could be slightly condensed without loss, but it is not wasteful.

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 absence of an output schema, the description compensates by fully enumerating return values (session_id, qr_payload, image variants, path), the intended flow (scan then poll), and time constraint. It is almost complete for a login initiation tool, though it does not mention failure behaviors or cleanup, which are minor for this context.

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, so the schema is empty and there is nothing to explain. The description instead focuses on outputs and flow, so the baseline of 4 is appropriate. It does not add parameter-specific info because none exist.

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 tool creates a QR login session without authentication, specifies the returned elements (session_id, qr_payload, QR code image), and differentiates from related siblings like login_qr_poll by explicitly mentioning the post-scan polling step. The verb-resource pairing is specific and unambiguous.

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 provides clear context for when to use (免鉴权) and explicitly directs the agent to call login_qr_poll after scanning, effectively distinguishing this from other login methods. However, it does not explicitly state when not to use it or mention alternatives like login_email or login_qr_recognize, though the flow is implied.

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