glass_window

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

Annotations (readOnlyHint: false, destructiveHint: false) already convey that the tool can mutate but is not dangerous. The description adds value by splitting behavior into mutating operations (focus, resize, move) and a read-only one (geometry). It does not, however, disclose consequences such as focus stealing, whether resize/move out-of-bound values are clamped, or whether geometry is returned in window-relative or screen coordinates beyond the x/y note in the schema.

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 sentence with a scannable op list, no filler, and the core action is front-loaded. It earns a 4 rather than 5 because the omitted target-window context and the shorthand 'window' without a definition make the sentence slightly under-specified rather than merely concise.

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 multi-operation tool with 5 parameters, the description plus schema covers dispatch semantics well, including per-param conditions and coordinates. But there is no output schema, and the description does not state what 'geometry' returns, which window the action applies to, or whether calls are relative to the currently active/selected window. These gaps are meaningful but partially offset by the very detailed schema.

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 100%, and each parameter description already explains its meaning, per-op requirements, and coordinate semantics. The tool description itself adds no new semantic detail beyond naming the op values. With full schema coverage, the baseline of 3 is appropriate; the description does not need to compensate.

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 names concrete verbs (focus, resize, move, read geometry) against a clear resource (the window), so an agent quickly understands what the tool does. It is distinguishable from siblings like glass_select_window and glass_move because the word 'window' anchors the resource. It loses a point for not stating which window is targeted or how that target is established.

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 'op: focus|resize|move|geometry' list implies usage dispatch, and the schema reinforces per-parameter conditions ('required there and ignored otherwise'), which is decent guidance. However, the description never says when to use this tool instead of related tools — for instance, whether the targeted window must first be selected via glass_select_window, or whether op:"move" is the right path versus the sibling glass_move. The guidance is implied rather than explicit.

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