Move/Resize Window

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

Discloses meaningful behavioral traits beyond annotations: requires Accessibility permission, returns a verified final frame, and notes that apps may clamp requested geometry. This adds context about safety and reliability that annotations (readOnly=false, destructive=false) do not fully capture.

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?

Three concise sentences, each serving a purpose: action, parameter grouping, and behavioral outcome. No fluff or repetition of schema details; information is front-loaded and easy to parse.

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 tool with five parameters and no output schema, the description is complete: it covers what it does, prerequisites, parameter combination rules, return behavior, and potential clamping. The sibling tools are distinct enough that no further caveats are needed.

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?

With 100% schema coverage, the baseline is 3, but the description adds value by clarifying the grouping logic (x and y together, width and height together, or both sets). This complements the schema's per-field 'requires' notes and helps the agent understand valid combinations at a glance.

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 action: 'Move and/or resize a window.' It distinguishes from siblings like window_focus and window_set_state by specifying exactly what geometry changes are performed. The independent handling of position and size adds specificity beyond the title.

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?

Provides clear context on how to use the tool (pass only x+y, only width+height, or both) and a prerequisite (requires Accessibility permission). However, it doesn't explicitly mention when not to use this tool or name alternatives, though the function is self-evident from the name and description.

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