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

Adds substantial context beyond the annotations: stateless edge call, 32 KB payload cap, 60 RPM rate limit, '?demo=true' trial path, L402 payment of 200 sats, and HTTP 400 on invalid input. It also explicitly reconciles the 'executes actions' framing with readOnlyHint=true by labeling itself a stateless read-only edge call, though it does not clarify whether side effects persist on the target UI.

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?

Purpose and sibling routing are front-loaded in the first two sentences, with operational constraints compressed into a final clause. Dense but nearly every clause carries information; the long parenthetical action list and the auth/payment clause make the last sentence feel packed.

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 an output schema present and rich annotations, the description only needed to add scope, routing, and operational limits — all of which it does. The remaining gap is what a caller should expect from the returned plan/action sequence and whether GUI actions are simulated versus applied.

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%, so both parameters are already documented, and the enum for viewport_preset is self-explanatory. The description adds the default preset value (already in the schema) and mentions the demo/L402 query flag, which is not an input property, so marginal value over structured fields.

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 first sentence names a specific verb (plans and executes) and enumerates the concrete resources/actions (OS-level desktop, browser DOM, GUI coordinates: click, type, scroll, wait) plus the underlying engine. It is immediately distinguishable from execute_antigravity_agent and other siblings without opening the schema.

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?

Explicit routing guidance: 'Use when automating interactive web UIs or desktop workflows that lack a direct REST API' and 'for running code-first API and terminal automation tasks, use execute_antigravity_agent instead.' Both the selection condition and the exclusion/alternative are stated.

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