get_ui_source

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

With no annotations, the description carries the burden of behavioral disclosure. It correctly implies a read-only getter operation via 'Get,' and adds the useful context that it's foundational for element queries. However, it doesn't mention potential edge cases or output size, leaving some gaps.

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?

Two sentences with no filler: the first states the core behavior, the second explains why it matters. It is front-loaded and efficiently worded.

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 simple tool with one optional parameter and no output schema, the description covers the primary return type (SceneGraph XML) and its main use case (writing element queries). It is sufficiently complete without needing to restate the parameter documentation.

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 coverage is 100% because the 'parsed' parameter has a clear description. The tool description adds no extra semantic meaning to the parameter, but none is needed since the schema already explains its effect on output format.

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 (get), the resource (current UI hierarchy), and the format (SceneGraph XML). It also emphasizes its role in understanding screen elements and writing queries, which distinguishes it from siblings like take_screenshot and find_element.

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 says the tool is 'essential for understanding what elements are on screen and writing element queries,' providing clear context for when to use it. It does not explicitly name alternatives or exclusions, but the implied usage is strong enough.

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