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

With annotations already covering safety traits, the description adds substantial behavioral context: the return value is a single-use expiring URL, the user signs in on that page, wait_for_sign_in completes the flow, failures return a list of supported sites, and re-signing in targets the same connection id.

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 purpose and trigger are front-loaded, and the multi-paragraph structure follows the workflow logically. It is longer than necessary but most sentences carry actionable detail for a complex sign-in flow.

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?

There is no output schema, so the description must explain return values; it does so with url and expiresAt. It also covers failure behavior, the next step with wait_for_sign_in, and the saved-login case, which is complete for this tool.

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 coverage is 100%, so the baseline is 3. The description adds meaning by explaining the connection parameter’s use case: signing back in to a saved login that stopped working, with the fresh session going into the same id.

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 states a specific verb and resource: get a sign-in link for one site. It distinguishes this tool from sibling tools by explaining that wait_for_sign_in is called afterward and that the user should not be sent to the extension or dashboard.

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 gives explicit triggers: call whenever the user asks to log in, sign in, connect, or link an account on a site. It also states when not to use it, names the follow-up tool, handles the saved-login case, and explains failure behavior.

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