get_ui_tree

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

With no annotations, the description carries the full transparency burden. It does disclose that the tool returns clickable elements with coordinates, which is a behavioral detail. However, it does not clarify whether the full tree is returned or only the clickable subset, nor does it state that the operation is safe/read-only. This is a minor gap for a simple getter.

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 two concise sentences, front-loading the core purpose ('Get the UI element tree') and using a helpful analogy ('like DOM but for Android') to add clarity. Every word earns its place; no fluff or repetition.

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 parameterless tool with no output schema, the description covers the essential behavior and return content. The only ambiguity is whether the tree includes all elements or just clickable ones, which could confuse an agent. Otherwise, the description is sufficiently complete for the tool's simplicity.

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?

The tool has zero parameters and schema coverage is 100%, so there is nothing to explain. The description does not need to compensate for missing parameter information. The baseline of 4 applies because with no parameters the description fully covers the input side.

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 tool gets the UI element tree of the device, using the DOM analogy to make it immediately understandable. It also specifies the key output (clickable elements with coordinates), which distinguishes it from siblings like screenshot or get_clipboard.

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 implies usage for inspecting the UI hierarchy ('like DOM but for Android'), but it does not explicitly contrast with overlapping siblings such as get_clickable_elements or get_all_text. No exclusion criteria or alternative recommendations are provided, so the guidance is only implied.

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