get_ui_tree

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

No annotations are supplied, so the description carries the full burden and does disclose that extraction happens over a fast RPC path and that returned elements carry [#index] handles for later targeting. It does not cover failure modes (missing accessibility service, empty trees) or read-only guarantees, but the behavioral picture is substantially richer than the name alone.

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 short lines, front-loaded with the core purpose, then the return shape, then the next-step affordance. Almost no wasted tokens despite the marketing framing.

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?

An output schema exists, and the description still summarizes the payload (index, class, text, desc, id, coordinates, flags), which is more than required. The remaining gap is disambiguation from the crowded set of sibling perception tools, which the definition never addresses.

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 all three parameters (keyword, max_elements, only_interactive) are self-documented in the schema. The description mentions none of them, so it adds no meaning beyond the structured fields and the baseline 3 applies.

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 (extract the semantic UI control tree of the current screen) and explicitly positions itself against a named alternative mechanism ('replaces slow screenshots'), so an agent can tell what it gets and why it beats screenshot_annotated.

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?

Clear usage context: use this for perception, then call tap_element(index=N) or tap_element(text=...) for the follow-up action. It stops short of distinguishing itself from the many overlapping perception siblings (ui_snapshot, inspect_view_hierarchy, find_elements, ui_describe, ui_query), so the agent must still guess among those.

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