previewapk_device

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

With no annotations, the description carries the full behavioral burden and does so well: it discloses the 10 MB file limit, /sdcard restriction, mock location persistence until cleared, locale relaunch need, reboot duration and data survival, recording-save behavior, and the absence of clipboard control.

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 compact for a nine-action tool and front-loads the overall purpose before listing each action with only the details needed to use it correctly. The final clipboard exclusion is also useful and wastes no space.

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?

Given the absence of annotations and output schema, the description covers nearly all operational behavior an agent needs, including limits and side effects. It does not describe return values for actions like list_files or pull_file, and it leaves the device parameter unexplained, which are minor but real gaps.

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 description adds substantial meaning beyond the 56%-covered schema: timezone examples, BCP 47 locale examples, default package behavior, location mock semantics, file size limits, list_files default folder, and reboot side effects. The only notable gap is the 'device' parameter, which is never explained.

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 frames the tool as device controls for QA and enumerates the specific supported actions, including timezone, locale, location, file operations, and reboot. It is highly distinguishable from interaction siblings like tap or swipe, though it does not explicitly contrast itself with previewapk_use_device or other device-management tools.

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?

Usage context is clear for each action: push_file for test fixtures, set_location creates a mock fix until cleared, set_locale is Android 13+ per-app language and may require app relaunch. It provides practical when-to-use cues but does not explicitly state when to choose this tool over sibling tools.

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