login

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

No annotations are provided, so the description fully carries the behavioral burden. It discloses that the browser opens non-headless, that login must be manually completed, that cookies are persisted per domain, and that timeout still saves current state—covering the key behavioral side effects.

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 well-structured with a short overview followed by an Args section. It is slightly verbose in places, but every part contributes useful operational context, and the key workflow information is 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?

Given the manual, interactive nature of this tool, the description covers the full call flow: why to invoke it, what the user will see, how the state is saved, and what happens after timeout. The existing output schema covers return values, so no additional explanation is needed.

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 0%, but the description fully documents both parameters: url specifies any page URL of the target site with login state keyed by domain, and timeout sets the manual-login waiting period with a defined timeout behavior. This adds substantial meaning beyond the bare 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?

The description opens with a specific verb and resource: opening a GUI browser for manual login and persisting the site's login state to disk. It also explicitly ties itself to the web_fetch login_required=true workflow, which clearly distinguishes it from the sibling fetch tools.

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 explicitly states when to use this tool: when web_fetch reports login_required=true for a site. It also explains the follow-up behavior (web_fetch will automatically carry the saved login state afterward), giving the agent clear situational guidance.

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