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

Annotations already indicate this is not a read-only operation (readOnlyHint: false) and uses an open world (openWorldHint: true). The description adds that it polls until the page leaves the sign-in surface or times out, which is useful behavioral context beyond the annotations. It doesn't mention error handling or side effects beyond 'continue fill', but the polling condition and timeout are disclosed. Given annotations carry some weight, this is solid but not exhaustive.

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, front-loaded sentence that states the trigger condition first, then the action, then the continuation. Every word earns its place; there is no fluff or repetition of schema details. It is concise and readable.

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?

The tool has an output schema, so return values are handled separately. The description covers the why, when, and what of the tool sufficiently. It could mention error behavior or default timeout values, but those are in the schema (defaults for pollMs and timeoutMs) and likely in the output schema. For a polling tool, this is reasonably complete.

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 schema covers 100% of the parameters, so the description doesn't need to compensate. The description mentions 'poll' and 'timeout', which map naturally to pollMs and timeoutMs, but adds no new meaning beyond what the schema provides. This is the baseline 3 for fully covered parameters.

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 exactly what the tool does: it polls until the page leaves the sign-in surface after a login/2FA request, then continues filling. It references the sibling 'request_user_action' directly, which distinguishes it from other tools like 'fill_fields' or 'confirm_and_submit'. The verb (poll) and resource (sign-in surface) are specific, and the temporal relationship to request_user_action is clear.

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 tells the agent when to use this tool: after request_user_action(login|2fa). It also hints at the continuation step ('Then continue fill'), implying the tool is a bridge between user authentication and form filling. It doesn't explicitly list alternatives or when not to use it, but the contextual trigger is strong enough to route an agent correctly.

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