Focus a window

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

No annotations are provided, so the description carries the entire behavioral burden. Beyond the hint that focus is a prerequisite for typing, it says nothing about failure modes (window id not found, window closed), whether focus raises/restacks the window, whether it steals focus from another display, or blocking behavior. For a state-changing UI operation with zero annotation coverage this is a substantial gap.

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?

One short, front-loaded sentence with a parenthetical that earns its place by explaining why the tool matters. Nothing is padded, though the brevity is partly the cause of the missing parameter and failure-mode detail.

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?

With two parameters, one required and undocumented, no annotations, and no output schema, the description leaves the agent unable to determine where `window_id` comes from or how to handle the multi-display `id` case. The only thing it fully answers is the high-level purpose.

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 description never mentions either parameter. Schema coverage is only 50%: `id` is documented as coming from display_open, but `window_id` — the one required parameter — is a bare integer with no source or format guidance anywhere. The description does not compensate for that gap.

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?

States a specific verb and resource ('Focuses a window') with the additional scoping detail 'inside the display', which makes the target unambiguous. It does not name the sibling that enumerates window ids (`windows`) or contrast itself with `wait_for_window`, so differentiation from siblings is only partial.

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?

'needed before typing into some apps' gives a concrete condition for reaching for this tool rather than `type`/`key` directly, which is real usage context. There are no explicit exclusions or named alternatives, so it stops short of a full when/when-not statement.

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