get_screen_xml

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

With no annotations, the description carries the full transparency burden. It discloses that the output is raw, normalized, and platform-specific (Android uiautomator vs iOS Appium/WDA). It does not explicitly state whether the operation is read-only, but the 'Get' wording and dump semantics imply a non-mutating snapshot, and the platform-specific detail adds meaningful context.

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 four concise sentences, front-loaded with the primary purpose and followed by platform details and usage guidance. Every sentence adds useful information with no repetition or filler.

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 one-parameter tool with an output schema (which likely documents the exact return structure), the description provides sufficient context: raw vs. readable, platform normalization, and when to use it. It is complete enough for an agent to select and invoke the tool correctly.

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?

There is one parameter, 'device', and the schema has 0% description coverage, meaning the description never mentions or explains the parameter. However, the parameter is self-explanatory from its type/name, and the description's 'from the device' implicitly references it. Still, the description adds no explicit parameter-level semantics beyond the schema.

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 starts with a specific verb and resource: 'Get the raw normalized UI XML dump from the device.' It clearly distinguishes the tool's output from get_screen_tree by noting it returns raw XML rather than a readable summary, and it also differentiates Android vs. iOS behavior.

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 usage guidance is provided: 'Use get_screen_tree() instead for a readable summary' and 'Use this only when you need exact attribute values or the full hierarchy.' This clearly states when to use the tool and when to prefer an alternative.

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