Focus i3 Window

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

The description adds value beyond annotations by stating the tool is reversible (consistent with idempotentHint=true and destructiveHint=false) and by explaining the rejection of invalid selector combinations. However, it could briefly mention that only focus is affected, not window position.

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 three sentences with no fluff: main purpose and selection options, reversibility, and important constraint/alternative. Front-loaded with key information.

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 complexity of 8 parameters and multiple selection methods, the description covers core behavior, constraints, and alternatives. Output schema exists, so omission of return value details is acceptable.

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?

Although schema coverage is 100%, the description groups parameters into categories (direction, criteria, parent/child, layer, output) and clarifies mutual exclusivity, which is essential semantics not present in individual schema descriptions.

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 clearly states the verb 'Move keyboard focus' and the resource (i3 window), and distinguishes from sibling `move_window` by specifying that this tool focuses, not moves. It also explains the selection mechanism and the constraint of exactly one selector.

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 names the alternative `move_window` for moving instead of focusing, and warns that supplying none or several selectors is rejected. This provides clear when-to-use and when-not-to-use guidance.

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