Stop a PreviewAPK session, ending the session and closing its preview link so the device is no longer shared. Use it when you are done driving the phone.
Stop the session. The session link dies with it. (previewapk_feedback files a field report about the tool — what broke, what worked, what you wish it had; reports directly shape what gets fixed and built next.)
| Name | Required | Description | Default |
|---|---|---|---|
| device | No |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It usefully discloses that the session link dies with the stop, which is important destructive context, but it does not explain whether device state is retained, whether the action is reversible, what permissions are required, or what happens to the optional device parameter.
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 core instruction is front-loaded and brief: "Stop the session. The session link dies with it." However, the parenthetical about previewapk_feedback is unrelated to invoking previewapk_stop and consumes space without helping the agent decide or act. The useful content is concise, but the included sibling advertisement reduces focus.
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 description covers the basic action and one key consequence, but with no annotations, no output schema, and an undocumented optional parameter, it leaves significant gaps. It does not explain how the device parameter affects the operation, what the tool returns, or how this stop differs from other session-ending tools in the sibling set.
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 one optional parameter, device, with 0% schema description coverage and only the type "string" documented. The description never mentions the device parameter, so it adds no meaning about what the parameter selects or how it affects which session is stopped. With low schema coverage, the description should compensate but does not.
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 states a specific verb and resource: "Stop the session." It also clarifies the immediate consequence that the session link dies. However, it does not distinguish this action from sibling tools such as previewapk_finish or previewapk_handoff, which may also end or transition a session.
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 gives no guidance on when to use this tool versus alternatives like previewapk_finish, previewapk_handoff, or previewapk_record_stop. It implies stopping the session but provides no exclusions, prerequisites, or decision criteria for an agent choosing among similar lifecycle tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.