focus

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

With no annotations, the description carries the burden and does disclose a useful behavior: it raises an exception if the element is not found within the default timeout. However, it does not mention side effects like scrolling, focus events, or whether the element must be visible, leaving part of the behavioral profile unstated.

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 two short sentences with no filler. The primary action is front-loaded, and the exception behavior is a useful secondary detail that earns its place.

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 one-parameter action with no annotations, the description covers the basic action and failure mode but omits selector semantics and any context for selecting this tool over similar element-targeting siblings. It is minimally adequate but not fully 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?

Schema description coverage is 0%, so the description must compensate for the undocumented selector parameter. It merely calls the target 'an element' and does not explain what selector syntax is accepted (e.g., CSS, XPath) or any constraints on selector values.

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 action ('Move focus') and a clear resource ('an element'), so an agent can grasp the tool's core purpose. It does not explicitly differentiate itself from siblings like click or highlight, which also target elements and affect interaction state.

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?

There is no guidance on when to use focus versus click, highlight, or keyboard-adjacent tools, nor any exclusions or alternatives. The only additional sentence describes failure behavior, not usage context.

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