Wait for LINE login

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

Beyond the annotations, the description and parameter schema disclose key behaviors: Chrome runs headless, a window pops only for QR scan, the user can log in via QR or email, and the tool settles briefly to prove headless reuse. It does not contradict the readOnlyHint, since the tool itself waits rather than performing a write.

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 a single concise sentence that names the action and the goal with no filler. The additional behavioral details are placed in the parameter schema where they belong, keeping the main description lean and front-loaded.

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 simple one-parameter wait tool with annotations and an output schema, the description covers the essential purpose and behavior. It does not mention timeout failure behavior or the case of an already-authenticated session, but those are minor gaps given the schema's timeout documentation.

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%, and the timeout_sec parameter has a thorough schema description including default, min, max, and behavioral context. The main description adds no additional parameter meaning, so the baseline of 3 is appropriate.

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 ('Open Chrome and wait') and the specific goal ('until the user finishes LINE login'). It is distinguishable from sibling tools like line_status or probe_session because it focuses on the interactive login wait, not on querying session state. It does not explicitly name siblings, so it falls just short of a 5.

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 gives clear context that this is the prerequisite login step: after login, later tools can call right away. It implies when to use it, but it does not state exclusions (e.g., 'skip if already logged in') or mention alternative session-check tools like probe_session.

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