ui_dump

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that the output is XML format ('as XML'), which is a valuable behavioral detail not in the annotations. It does not disclose potential size/verbosity of the dump, but given annotation coverage, the bar is lower and the description 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?

A single, compact sentence conveys the action, scope, and output format without any filler. Every element earns its place. There is nothing extraneous to trim.

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?

The tool takes one optional parameter (serial, fully described in schema), has an output schema (so return format is specified structurally), and carries readOnly/openWorld annotations. The task is simple—dump the UI hierarchy—and the description adequately communicates purpose and output format for this low-complexity operation. Could note potential verbosity of large dumps but the tool's simplicity doesn't demand much more.

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%, meaning the 'serial' parameter is fully described in the schema as the device serial number. The description adds no additional parameter semantics, which matches the baseline of 3 when schema covers everything. No compensation needed.

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 verb+resource: 'Dump the full UI hierarchy of the current screen as XML.' It specifies both the action (dump) and the object (full UI hierarchy). However, it doesn't explicitly distinguish itself from sibling tools like ui_find_element or ui_get_state, which also relate to UI inspection, though the full-hierarchy XML scope is fairly distinct.

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 complete screen layout but doesn't provide explicit when-to-use guidance or contrast with alternatives like ui_find_element (targeted search) or ui_get_state (state extraction). Since multiple UI inspection tools exist among siblings, clearer guidance on when to use a full dump vs targeted queries would improve selection accuracy.

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